THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

GIFT  OF 

Dan  Gutleban 


COKE 

A  TREATISE  ON  THE 

MANUFACTURE  OF  COKE  AND  OTHER 
PREPARED  FUELS 

AND  THE 

SAVING  OF  BY-PRODUCTS 


WITH  SPECIAL  REFERENCES  TO  THE  METHODS  AND  OVENS  BEST  ADAPTED 

TO  THE  PRODUCTION  OF  GOOD  COKE  FROM  THE 

VARIOUS  AMERICAN  COALS 


BY 

JOHN  FULTON,  A.  M.,  E.  M. 

Member  of  American  Institute  of  Mining  Engineers, 

American  Philosophical  Society  of 

Philadelphia,  Etc. 


SCRANTON,  PA. 
INTERNATIONAL  TEXTBOOK  COMPANY 

1906 


Copyright,  1895,  by  THE  COLLIERY  ENGINEER  COMPANY 

Copyright,  1905,  by  INTERNATIONAL  TEXTBOOK  COMPANY 

Entered  at  Stationers'   Hall,  London 

All  rights  reserved 
Printed  in  the  United  States 


LOAN  STACK . 
GIFT 


B- -17303 


PREFACE  TO  SECOND  EDITION 


The  first  edition  of  Coke  was  issued  by  The  Colliery  Engineer 
Company,  of  Scranton,  Pennsylvania,  in  the  year  1895  and  was  the 
first  treatise  on  this  growing  and  important  industry  published  in 
the  United  States  of  North  America.  This  edition  was  exhausted 
over  one  year  ago. 

In  the  great  progress  of  industrial  manufacturers  so  manifest  in 
the  United  States,  this  interval  of  nine  years  since  the  appearance 
of  the  first  edition  has  retired  some  of  the  former  methods  in  the 
manufacture  of  coke,  and  introduced  many  new  ones.  This 
advance  in  the  progress  of  the  industry  has  been  induced  by  the 
large  increase  in  the  demand  for  coke,  arising  from  the  expansion 
in  the  use  of  steel  and  iron  in  architectural  construction,  as  well  as 
in  railroad  supplies.  In  the  manufacture  of  these  materials,  a  pure 
quality  of  coke  fuel  is  an  imperative  necessity,  and  with  the  con- 
sequent large  demand  on  the  best  coking  coal  fields,  it  has  become 
necessary  to  extend  coking  operations  outside  these  fields  to  regions 
possessing  coking  coals  of  a  lower  grade,  requiring,  in  most  cases, 
cleansing  from  the  two  principal  impurities,  slate  and  sulphur,  by 
the  modern  processes  of  crushing,  classifying,  and  washing. 

This  necessary  preparation  or  cleansing  of  coals  for  coking  has 
been  an  inviting  field  for  mechanical  experts  in  which  to  devise 
machinery  for  this  special  purpose.  It  has  also  impressed  the 
necessity  for  studying  the  several  conditions  in  which  these  foreign 
matters  are  found  in  coals,  so  that  proper  machinery  could  be 
devised  to  meet  the  several  conditions  necessary  for  eliminating 
slate  and  sulphur. 

This  department  of  the  coke  industry  has,  during  the  past 
decade,  made  commendable  progress,  especially  in  the  preparation 
of  the  coal  for  introduction  into  the  washer,  in  disintegrating  the 
lumps  of  coal  to  certain  sizes,  and  in  the  classification  of  the  crushed 
product  as  it  is  being  conveyed  into  the  washers.  This  important 
auxiliary  in  the  manufacture  of  coke  enables  the  lower  qualities 
of  coals  to  be  utilized  in  the  production  of  an  acceptable 
metallurgical  fuel. 

In  addition  to  this  coal-cleansing  auxiliary  in  the  coke  industry, 
an  additional  element  has  been  introduced,  meeting  the  conditions 
of  some  coals  low  in  bituminous  matter  —  dry  coals  —  in  a  fairly 
satisfactory  manner.  These  dry  coals,  low  in  fusing  matter,  could 

iii 


8S7 


iv  PREFACE  TO  SECOND  EDITION 

not  be  made  to  produce  the  best  possible  product  in  the  usual  open 
beehive  coke  oven.  To  meet  these  exceptional  conditions,  the 
retort  coke  oven  has  been  introduced ;  it  is  made  in  several  types, 
but  the  different  types  have  one  element  in  common — the  retort  or 
closed-chamber  principle,  which  affords  a  quick  heat  and  permits  the 
utilization  of  the  small  content  of  volatile  matter  in  these  dry  coals. 

The  large  cost  of  these  retort  coke  ovens,  with  the  additional 
expense  of  the  apparatus  for  saving  the  by-products  of  tar  and 
ammoniacal  liquor,  has  prevented  their  general  introduction.  In 
addition  to  the  large  cost  of  installation,  a  retort-oven  plant  requires 
a  supply  of  coal  for  a  long  period  to  cover  the  investment  in  the 
plant  of  ovens.  Only  certain  localities  can  assure  this  supply  of 
coal,  and  unless  the  conditions  of  the  manufacture  will  bear  the 
railroad  freight  charges  necessary  to  continue  the  coal  supply,  when 
it  has  to  be  obtained  outside  the  immediate  limits  of  the  coke  plant, 
a  retort-oven  plant  is  impracticable.  In  situations  where  water 
transportation  can  be  secured,  with  its  moderate  freight  rates,  the 
coal  supply  can  usually  be  secured  for  long  periods. 

The  use  of  the  by-product  tar  in  roofing  and  other  applications, 
with  its  anticipated  use  as  a  bonding  element  in  the  manufacture  of 
briquets,  will  enhance  the  value  of  this  by-product. 

In  the  first  edition,  the  conditions  were  submitted  that  com- 
pelled the  writer,  in  1875,  then  General  Mining  Engineer  of  the 
Cambria  Iron  Company,  to  the  study  of  the  physical  properties  of 
blast-furnace  coke.  At  that  time  the  blast  furnaces  of  this  com- 
pany were  supplied  mainly  by  coke  made  from  native  coals  in 
Belgian  ovens  located  at  the  works  in  Johnstown.  This  home-made 
coke  failed  when  the  expansion  of  the  steel  industry  required  the 
smelting  of  the  Lake  Superior  iron  ores  in  the  production  of  Besse- 
mer pig  iron.  The  furnaces  became  hot  above  and  cool  below,  and 
the  general  manager,  the  late  Hon.  Daniel  J.  Morrell,  requested  an 
investigation  of  the  cause  or  causes  of  the  inefficiency  of  this  coke 
fuel  in  the  blast-furnace  work. 

Chemical  analyses  failed  to  disclose  the  trouble,  as  the  native 
coke  was  found  to  be  much  purer  than  the  celebrated  Connel.lsville. 
This  result  came  as  a  disagreeable  surprise,  causing  a  general  search 
of  authorities  on  fuels  for  light  on  this  matter,  but  without  helpful 
results.  After  a  careful  examination  and  study  of  the  principal 
blast-furnace  fuels,  anthracite  coal,  charcoal,  Connellsville  and 
Johnstown  cokes,  it  became  evident  that  as  chemical  investigation 
had  failed  to  disclose  the  value  of  these  fuels,  it  must  be  determined 
by  physical  research. 

In  this  investigation  it  became  evident  that  two  principal 
requirements  were  demanded  in  blast-furnace  fuel :  hardness  of  body 
and  fully  developed  cellular  structure;  the  first  property  to  resist 
the  dissolution  of  the  fuel,  in  its  passage  down  the  furnace,  from  the 
attack  of  hot  carbonic-acid  gas,  and  the  second  to  assure  its  rapid 
combustion  and  calorific  energy  in  the  melting  zone  of  the  furnace. 


PREFACE  TO  SECOND  EDITION  v 

The  hardness  of  the  body  of  the  coke  was  determined  in  the 
usual  way.  The  cellular  space  was  determined  by  accurately  cut- 
ting inch  cubes,  weighing  them  dry  and  in  water,  and  equating 
conditions  to  determine  the  cell  space  in  the  body  of  the  cokes. 
The  home-made  coke  was  condemned  from  its  lack  of  hardness  of 
body,  while  the  Connellsville  became  the  standard  of  blast-furnace 
fuels  from  its  hardness  of  body  and  full  cell  development. 

The  author  believes  that  he  was  the  first  to  originate  this  course 
of  investigation  of  blast-furnace  fuels.  Some  criticism  followed 
the  early  results  of  these  investigations,  but  the  fact  of  priority  in  it 
has  not  been  questioned.  During  the  meeting  of  the  American 
Institute  of  Mining  Engineers,  at  Roanoke,  Virginia,  in  June,  1883, 
Mr.  Fred  G.  Dewey,  Washington,  District  of  Columbia,  a  representa- 
tive of  the  National  Museum,  in  submitting  a  paper  on  the 
"Porosity  and  Specific  Gravity  of  Coke,"  said:  "So  far  as  I  am 
aware,  the  credit  of  the  first  systematic  investigation  of  the  physical 
properties  of  coke  belongs  to  Mr.  John  Fulton,  Mining  Engineer 
of  the  Cambria  Iron  Company." 

In  a  recent  publication  on  the  chemistry  of  coke,  being  the 
"Grundlagen  Der  Koks-chemie"  by  Herr  Oscar  Simmersback, 
translated  and  enlarged  by  W.  Carrick  Anderson,  M.  A.,  B.  Sc.,  of 
Glasgow,  Scotland,  it  is  submitted  in  the  introduction:  "Upon  the 
physical  properties  of  coke,  experiments  were  carried  out  first  of  all 
by  Americans.  In  1875,  John  Fulton,  then  manager*  of  the 
Cambria  Iron  Works  Company,  at  Johnstown,  Pennsylvania,  dis- 
cussed the  variable  action  in  the  blast-furnace  fuels  containing  the 
same  quantity  of  carbon.  This  variability  he  ascribed  to  the  differ- 
ence in  their  physical  condition,  anthracite,  coke,  and  wood  charcoal 
being,  as  he  showed,  characteristicallv  unlike  in  structure."  (Iron, 
1884,  No.  602;  Berg-and  Huttenmannische  Zeitung,  1844,  p.  526.) 

The  author  appreciates  that  in  this  wide  field  of  research  there 
remains  very  much  to  be  disclosed,  but  he  trusts  that  this  contribu- 
tion may  be  helpful,  especially  in  a  practical  way,  to  those  interested 
or  engaged  in  this  large  and  expanding  industry — the  manufacture 
of  coke. 

In  the  preparation  of  this  second  edition,  the  author  has  neces- 
sarily drawn  from  various  sources,  and  due  acknowledgment  of 
such  help  has  been  given  in  the  text  whenever  it  has  been  possible 
to  do  so.  He  is  laid  under  many  obligations  to  the  several  publi- 
cations of  the  United  States  Geological  Survey,  especially  in  the 
valuable  "Twenty-Second  Annual  Report,  1900-1901,  Part" 3,  Coal, 
Oil,  Cement;"  and  to  the  very  comprehensive  annual  volume,  "The 
Mineral  Statistics  of  the  United  States."  Correspondence  and 
requests  with  this  important  department  of  the  government  have 
always  received  prompt,  accurate,  and  courteous  responses. 

*At  the  time  noted  above  by  Mr.  Anderson,  Mr.  Fulton  was  the  General 
Mining  Engineer  of  the  Cambria  Iron  Company;  subsequently  he  became 
General  Manager. 


vi  PREFACE  TO  SECOND  EDITION 

To  Mr.  James  M.  Swank,  General  Manager  of  the  American  Iron 
and  Steel  Association  at  Philadelphia,  he  is  indebted  for  valuable 
statistics  and  helpfulness  in  the  chapter  on  Briqueting. 

Mr.  J.  V.  Schaefer,  formerly  engineer  of  the  Link-Belt  Machinery 
Company,  of  Chicago,  but  now  of  the  firm  of  Roberts,  Schaefer  & 
Co.,  Engineers,  Chicago,  Illinois,  has  contributed  largely  to  chapter 
III,  on  the  preparation  of  coals  for  coking,  especially  on  the  treat- 
ment in  the  Luhrig  washer. 

Messrs.  Stein  and  Boericke,  Metallurgical  Engineers,  Primos, 
Delaware  County,  Pennsylvania,  have  contributed  much  matter  on 
the  treatment  of  coals  by  crushing  and  washing,  in  preparation  for 
coking. 

The  Semet-Solvay  Company,  of  Syracuse,  New  York,  has  con- 
tributed drawings  and  statistics  showing  the  size,  product,  and  cost 
of  the  Semet-Solvay  retort  coke  oven. 

Dr.  F.  Schniewind,  of  New  York,  has  furnished  many  drawings 
of  the  Otto-Hoffman  and  other  retort  coke  ovens  and  statistics  of 
its  work. 

Mines  and  Minerals,  a  monthly  journal,  published  by  the  Inter- 
national Textbook  Company,  Scranton,  Pennsylvania,  has  been 
largely  drawn  upon  for  matter  that  has  been  used  in  several  chapters 
of  this  edition. 

Extracts  have  also  been  made  from  several  volumes  of  the  trans- 
actions of  the  American  Institute  of  Mining  Engineers. 

Valuable  help  has  been  cheerfully  afforded  by  the  several  invent- 
ors of  coke  ovens,  disintegrating  machinery  and  washeries,  as  well 
as  from  managers  of  coking  establishments. 

In  the  full  chapter  on  "Briqueting  in  Europe  and  America," 
the  reports  of  the  United  States  consular  service  have  been  largely 
utilized  in  presenting  and  illustrating  this  young  industry. 

Sincere  thanks  are  returned  to  the  many  others  who  have  so 
kindly  contributed  to  the  matter  in  the  pages  of  this  second  edition. 

JOHN  FULTON. 

Johnstown,  Pennsylvania,  January  1,  1905. 


PREFACE  TO  FIRST  EDITION 


The  manufacture  of  coke  in  the  United  States  of  North  America 
began  in  a  feeble  way  with  four  small  establishments  in  the  year 
1850.  During  the  30  years  following,  the  progress  of  the  industry 
was  rather  slow,  but  from  1880  to  1892  it  made  rapid  advances, 
showing  in  the  latter  year  261  establishments,  using  42,002  coke 
ovens  and  producing  12,010,829  tons  of  coke,  valued  at  $23,536,141 
at  the  ovens. 

In  the  year  1869,  coke  outranked  charcoal  for  use  in  blast  fur- 
naces; and  in  1875,  it  surpassed  anthracite  coal.  Since  the  latter 
date,  it  may  be  said  that  we  fully  entered  into  the  era  of  coke.  It  is 
also  evident  that  this  coke  fuel  is  destined  to  retain  this  leading 
place  of  usefulness  in  metallurgical  operations,  and  its  increase  is 
destined  to  accompany  the  expansion  of  the  iron  and  steel 
industries. 

In  considering  the  present  condition  and  future  requirements  of 
the  coke-making  industry,  with  its  paramount  value  in  the  manu- 
facture of  iron  and  steel,  it  appeared  that  a  volume  embracing  the 
principles  and  practice  of  the  manufacture  of  coke  would  prove  of 
permanent  value  to  those  engaged  in  these  correlated  industries. 
Its  publication  is  regarded  as  the  more  needful  at  this  time  on 
account  of  the  efforts  being  made  to  introduce  the  modern  types  of 
retort  coke  ovens,  with  their  auxiliary  apparatus  for  saving  the  chief 
by-products — tar  and  sulphate  of  ammonia — from  the  gases 
expelled  in  coking,  and  thus  supplementing  the  profits  in  the  coke 
industry. 

In  the  United  States,  the  manufacture  of  coke  has  hitherto  been 
confined  mainly  to  localities  affording  the  best  qualities  of  coking 
coals.  It  required  little  skill  to  make  excellent  coke  from  such 
good  coals,  but  with  the  large  expansion  of  the  production  of  coke, 
and  the  gradual  exhaustion  of  the  areas  of  the  prime  coking  coals, 
compelling  the  use  of  the  secondary  qualities  of  coking  coals,  a 
thorough  study  of  the  merits  of  the  several  kinds  of  coke  ovens 
now  being  offered  is  regarded  of  the  most  important  interest. 

In  this  volume,  the  papers  on  the  manufacture  of  coke  that  have 
been  published  in  The  Colliery  Engineer  and  Metal  Miner,  have 
been  recast  and  carefully  revised.  They  give  the  several  methods 
of  coking,  with  the  results  obtained,  for  the  consideration  of  those 
interested  in  this  industry. 

vii 


viii  PREFACE  TO  FIRST  EDITION 

The  a'uthor  feels  that  very  much  remains  to  be  learned  in  this 
department  of  industrial  art,  but  trusts  that  this  initial  volume  will 
suggest  matter  that  will  lead  to  an  accelerated  advance  in  useful 
knowledge  along  the  several  sections  embraced  in  its  pages. 

The  work  has  been  undertaken  with  a  feeling  of  the  difficulty  of 
doing  it  the  justice  its  importance  deserves.  But,  in  this  respect, 
the  author  trusts  that  some  truth  has  been  gleaned  under  the  con- 
ditions of  the  old  adage  that  "  necessity  is  the  parent  of  invention." 

In  the  20  years'  experience  of  the  author,  in  his  official  position 
of  General  Mining  Engineer  and  General  Manager  of  the  Cambria 
Iron  Company,  he  has  been  required  to  study  the  manufacture  of 
coke  in  its  elements  of  quality  and  cost.  The  extensive  operations 
•  of  this  company  in  the  different  sections  of  the  Appalachian  coal 
region,  by  several  methods  of  coking,  afforded  desirable  oppor- 
tunities for  investigation  and  for  the  comparison  of  results. 

In  the  year  1875,  the  coke  made  at  the  works  at  Johnstown,  in 
Belgian  coke  ovens,  failed  to  meet  the  furnace  requirements.  The 
management  requested  an  investigation  of  the  cause  or  causes  of  the 
inefficiency  of  this  fuel  in  blast-furnace  work.  It  appeared  at  first 
to  be  an  easy  task  to  ascertain  the  nature  of  the  defect  or  defects  in 
this  coke.  It  was  assumed  that  a  chemical  analysis  would  disclose 
the  whole  matter,  but,  contrary  to  expectation,  it  did  not ;  it  showed 
the  coke  to  be  very  pure,  with  much  less  ash  than  the  Connellsville 
coke,  and  with  marked  exemptness  from  other  injurious  elements. 
The  result  compelled  an  expansion  of  the  method  of  investigation, 
as  the  chemical  method  alone  would  not  reveal  the  cause. 

A  study  to  devise  a  method  for  the  physical  examination  of  the 
coke  was  then  entered  upon,  which,  after  many  trials,  resulted  in 
developing  a  plan  that  disclosed  the  main  cause  of  the  failure  of  this 
coke  for  blast-furnace  use — its  want  of  the  principal  requirement, 
hardness  of  body.  From  the  softness  of  the  body  of  this  coke, 
much  of  it  was  wasted  in  the  upper  section  of  the  blast  furnace  by 
dissolution  in  the  bath  of  the  ascending  carbon-dioxide  gas,  thus 
lowering  the  temperature  at  the  zone  of  fusion,  and  disarranging  the 
regular  operations  of  the  workings  of  the  furnace. 

These  early  methods  of  testing  the  physical  properties  of  coke 
were  very  crude  and  open  to  criticism,  but  the  urgency  of  neces- 
sity, it  is  believed,  has  ultimately  disclosed  accurate  methods  of 
determining  the  true  value  of  coke  for  metallurgical  uses,  the 
practical  results  in  furnace  work  sustaining  the  reliability  of  these 
determinations. 

It  has  become  evident  in  the  manufacture  of  coke  from  the 
secondary  qualities  of  coking  coals,  that  from  the  nature  of  the 
requirements  of  quick  and  high-oven  heat  to  secure  the  hardest- 
bodied  coke  possible  from  such  coal,  the  retort  type  of  coke  ovens 
will  have  to  be  used. 

It  is  confidently  hoped  that  the  plans  and  statements  of  the 
actual  work  of  these  retort  ovens,  with  and  without  apparatus  for 


PREFACE  TO  FIRST  EDITION  ix 

the  saving  of  by-products,  will  prove  helpful  in  enabling  the  coke 
manufacturer  to  make  intelligent  selection  and  application  of  the 
special  type  of  oven  best  adapted  to  assure  the  best  coke  from  the 
coal  used  in  its  manufacture. 

Very  much  care  has  been  given  to  the  consideration  of  the  best 
modern  methods  in  the  preparation  of  coals  for  coking,  especially 
to  the  process  of  crushing  and  washing,  for  the  elimination  of  slate 
and  pyrites. 

In  the  preparation  of  this  work,  the  author  has  necessarily  drawn 
from  many  sources,  and  due  acknowledgment  for  such  help  will  be 
given  when  possible  to  do  so.  He  is  laid  under  many  obligations  to 
Mr.  Joseph  D.  Weeks,  of  Pittsburg,  for  extracts  from  his  admirable 
reports  for  statistics  of  the  manufacture  of  coke,  and  for  the  results 
of  his  recent  visit  to  Europe.  Mr.  Walter  M.  Stein,  metallurgist, 
Philadelphia,  agent  for  the  Siebel  retort  coke  oven,  has  kindly  con- 
tributed many  papers  on  plans  and  work  of  coke  ovens.  Dr.  F. 
Schniewind,  of  Cleveland,  Ohio,  agent  of  Dr.  C.  Otto  &  Co.,  has 
generously  contributed  very  full  information  of  the  plan,  cost,  and 
work  of  the  Otto-Hoffman  oven.  Mr.  W.  B.  Cogswell,  general  mana- 
ger of  the  Solvay  Process  Company,  of  Syracuse,  New  York,  has 
kindly  contributed  plans  and  results  of  the  working  of  the  plant  of 
Semet-Solvay  coke  ovens  at  his  place. 

The  author  is  also  placed  under  renewed  obligations  to  Sir  Isaac 
Lowthian  Bell,  of  England,  for  plans  of  his  Browney  coke  ovens, 
and  for  his  admirable  method  of  testing  the  resistance  of  coke  to  the 
action  of  carbon  dioxide. 

Mr.  Henry  Aitken,  Falkirk,  Scotland,  has  kindly  contributed  his 
plans  and  studies  in  his  methods  of  saving  by-products  from  bee- 
hive ovens. 

The  "Mineral  Statistics  of  the  United  States,"  by  Dr.  David  T. 
Day,  of  Washington,  District  of  Columbia,  has  afforded  much  help 
in  many  ways;  as  have  also  the  works  of  the  Second  Geological 
Survey  of  Pennsylvania,  by  Prof.  J.  P.  Lesley,  State  Geologist,  and 
his  able  assistants.  Many  valuable  extracts  have  been  made  from 
the  several  volumes  of  the  transactions  of  the  American  Institute  of 
Mining  Engineers. 

Sincere  thanks  are  returned  to  the  many  others  who  have  so 
kindly  contributed  to  the  matter  in  the  pages  of  this  volume. 


CONTENTS 


PREFACE  TO  SECOND  EDITION. 
PREFACE  TO  FIRST  EDITION. 


CHAPTER  I 


THE  COAL  FIELDS  OF  NORTH  AMERICA  ..............................  1 

The  Coal  Periods  ............................................  4 

Coal  Fields  of  the  United  States  ...............................  5 

The  Anthracite  Fields  ........................................  5 

Coal  Fields  of  Canada  ........................................  16 

Mexican  Coal  Fields  ................  .  .........................  17 

CHAPTER  II 

THE  FORMATION  AND  CHEMICAL  PROPERTIES  OF  COAL  ................  19 

Composition  of  Coking  Coals  ..................................  24 

Fusibility  and  Coking  Properties  ...............................  31 

Impurities  in  Coal  ............................  .  ...........    .  .  38 

CHAPTER  III 

PREPARATION  OF  COALS  FOR  THE  MANUFACTURE  OF  COKE  .............  43 

Crushing  Coal  ...............................................  46 

Coal  Washing  .............................................  56 

Trough  Washers  .............................................  57 

Jigs  .......................................................  61 

Brookwood,  Ala.,  Washery  ....................................  75 

Coal-Washing  Plant  for  Bituminous  Coals  at  Coahuila,  Mex  .......  79 

Improvement  of  Coal  Effected  by  Washing  .....................  97 

Robinson  Coal  Washer  Plant  ..................................  99 

The  Liihrig  Washer,  Dowlais,  Wales  .......................  ....  101 

The  Liihrig  Washer,  Nelsonville,  Ohio  ..........................  108 

The  Liihrig  Washery  at  Punxsutawney,  Pa  ......................  110 

The  Stewart  Coal  Washer  .....................................  113 

Stein  &  Boericke  Washer  .....................................  122 

Baum  Washer.  .  .  ............................................  123 

A  Baum  Washing  Plant  at  Gladbeck,  Westphalia  ................  128 

Washer  for  Fine  Coal.  .  .129 


xii  CONTENTS 

CHAPTER  IV  page 

HISTORY  AND  DEVELOPMENT  OF  THE  COKE  INDUSTRY 131 

Statistics  Showing  Development  of  Coke  Industry 133 

Coal  Required  to  Produce  1  Ton  of  Coke 137 

CHAPTER  V 

MANUFACTURE  OF  COKE 145 

Methods  of  Coking  Coal 145 

Coking  Coal  in  Heaps  or  Mounds 145 

To  Determine  Loss  of  Carbon  in  Process  of  Coking 147 

Beehive  Coke  Oven 148 

The  Coking  Process : 157 

Old  Welsh  Oven 164 

The  Thomas  Oven 164 

Browney  Coke  Plant 167 

Use  of  Waste  Gases  for  Steaming  at  Pratt  Mines,  Ala 169 

The  Ramsay  Patent  Beehive  Coke  Oven 173 

Daube's  Economic  Down-Draft  Coke  Oven 177 

Improved  Heminway  Process 178 

Newton-Chambers  System 186 

The  Smith  Coke  Drawer 187 

The  Hebb  Coke  Drawer 188 

Silica  Brick 191 

Coking  Experiments  and  Results 192 

Effects  in  Physical  Properties  of  Coke  Produced  by  Crushing  the 

Coal 195 

CHAPTER  VI 

RETORT  AND  BY-PRODUCT-SAVING  COKE  OVENS   200 

Introduction 200 

The  Belgian  Oven 206 

The  Coppe'e  Coke  Oven 208 

The  Appolt  Coke  Oven 212 

Comparison  of  Oven  Types 214 

Modification  of  Appolt  Coke  Ovens  at  Blanzy. . 215 

Simon-Carves  Ovens 219 

G.  Seibel's  Retort  Coke  Oven 223 

Manufacture  of  Sulphate  of  Ammonia 232 

Otto-Hoffman  Retort  Coke  Oven 235 

Otto-Hoffman  Ovens  and  By-Product  Apparatus  of  the  Pittsburg 

Gas  and  Coke  Co 248 

The  Schniewind  Oven 252 

Utilization  of  the  By-Products  of  the  Coke  Industry 256 

Festner-Hoffman  Coke  Oven 7* 260 

Semet-Solvay  Coke  Oven 263 

West  Virginia  Coals  in  Semet-Solvay  Ovens  ,  268 


CONTENTS  xiii 

Page 

Semet-Solvay  Plant  at  Dunbar,  Pa 273 

Connellsville  Coke  from  Semet-Solvay  Ovens   277 

The  Rothberg  By-Product  Coke  Oven 290 

The  A.  Hiissner  Coke  Oven 291 

The  Bernard  Coke  Oven 294 

The  Brunck  Coke  Oven 298 

The  Bauer  By-Product  Coke  Oven 302 

The  Lowe  Coke  Oven 306 

The  New  Lowe  Coke  Oven  and  Gas-Making  System 306 

Beehive  By-Product  Oven 311 

The  Manufacture  of  Coke  From  Compressed  Fuel .  312 

Coke  Pusher 318 

Coal-Distillation  Plant  at  the  Matthias  Stinnes  Mines  in  Carnap, 

Germany . 320 

CHAPTER  VII 

PHYSICAL  PROPERTIES  OF  CHARCOAL,  ANTHRACITE,  AND  COKE,  AND  A 

COMPARISON  OF  BEEHIVE  AND  BY-PRODUCT  COKE 326 

Comparison  of  Beehive  and  By-Product  Coking 335 

Effects  of  the  Several  Types  of  Coke  Ovens  on  the  Physical  Prop- 
erties of  Their  Coke  Products 348 

CHAPTER  VIII 

THE  LABORATORY  METHODS  OF  DETERMINING  THE  RELATIVE  CALOR- 
IFIC VALUES  OF  METALLURGICAL  FUELS 353 

CHAPTER  IX 

THE  LOCATION  OF  PLANTS  FOR  THE  MANUFACTURE  OF  COKE 361 

The  Morrell  Plant 364 

No.  3  Plant,  H.  C.  Frick  Coke  Co 365 

Oliver  Plant 366 

Coke  Making  for  Profit 369 

American  Coke  Company's  Plant 375 

The  Hostetter  Connellsville  Coke  Company's  Works 375 

The  Joseph  Wharton  Coke  Plant 376 

Retort  Oven  Plants 379 

Production  of  Illuminating  Gas  From  Coke  Ovens 381 

The  Everett  Coke  Oven  Gas  Plant 384 

CHAPTER  X 

GENERAL  CONCLUSIONS  ON  THE  WORK,  COST,  AND  PRODUCTS  OF  THE 

SEVERAL  TYPES  OF  COKE  OVENS 392 

Comparison  of  Different  Types  of  Ovens 397 

Advisability  of  Saving  By-Products 401 


xiv  CONTENTS 

CHAPTER  XI  page 

THE  FUEL  BRIQUETING  INDUSTRY 406 

Composition  of  Briquets 409 

Methods  and  Cost  of  Manufacturing  Briquets 417 

Briqueting  in  Austria-Hungary 417 

Briqueting  in  Belgium 419 

Briqueting  in  France 422 

Briqueting  in  Germany ....'. 433 

Peat  Manufacture 439 

Briqueting  in  Norway  and  Sweden 445 

Briqueting  in  Great  Britain 448 

Briqueting  in  Canada 453 

Briqueting  in  the  United  States 462 


TREATISE  ON  COKE 


CHAPTER  I 


THE  COAL  FIELDS  OF  NORTH  AMERICA 

Importance  of  Coal. — Geology,  like  history,  has  its  special  and 
important  epochs.  The  coal-making  periods  are  the  most  remark- 
able in  the  geology  of  our  planet,  for,  during  these  periods,  the 
great  deposits  of  mineral  fuel  were  stored  up,  anticipating  and  pro- 
viding for  the  wants  of  the  coming  man,  in  the  order  of  his  com- 
fort, civilization,  and  poWer. 

Among  all  the  valuable  gifts  the  Creator  has  bestowed  upon 
man,  coal  is  the  most  essential  to  his  well  being  and  progress.  It 
is  true  that  man  could  exist,  under  the  beneficence  of  the  sun's 
warmth  and  the  fuel  from  the  vegetation  of  the  field  and  forest; 
but  it  is  clearly  evident  that  to  attain  the  best  conditions  of  civili- 
zation and  power,  he  must  have  the  fuel  supply,  the  stored  up  and 
crystallized  sunlight,  of  the  old-time  coal-making  periods. 

The  value  of  this  coal  endowment  has  now  become  a  standard 
by  which  the  nations  of  the  world  are  classified  as  to  their  present 
power  and  future  progress.  Recent  experience  has  emphasized 
the  vital  importance  of  this  coal  supply. 

From  our  present  knowledge  of  the  extent  of  the  coal  fields, 
the  following  graphic  comparison  will  exhibit  the  relative  ranks 
of  the  nations  of  the  world  in  their  possessions  of  coal. 

This  graphic  comparison  of  coal  areas  shows  that  the  United 
States  of  America  inherits  a  wealth  of  coal,  so  far  as  developed, 
equal  to  that  possessed  by  all  the  other  countries  of  the  world. 

Future  explorations  will  doubtless  increase  the  area  of  coal  in 
the  United  States,  British  America,  and  in  the  less-developed 
countries  of  foreign  lands.  The  production  represented  by  the 
square  for  "Other  Countries"  will  in  all  probability  be  greatly 
increased  in  the  near  future  as  the  deposits  of  China  and  Japan 
are  opened  up.  The  United  States  need  be  in  no  fear  of  losing 
first  place,  however,  at  least  for  a  long  time.  In  1899  we  wrested 
first  place  from  Great  Britain  and  our  production  is  steadily 
increasing  and  widening  the  gap. 


TREATISE  ON  COKE 


COAL  FIELDS  OF  THE  WORLD— 1902 


United  States  of  America 


344,440  square  miles 


British  America    •       • 60,000  square  miles 


Great  Britain !• 12,000  square  miles 

Spain    J| 4,000  square  miles 

France    _^_ 2,000  square  miles 

Germany    g_ 1,800  square  miles 

Belgium   m 600  square  miles 


Other  Countries   . 


—    110,000  square  miles 


TREATISE  ON  COKE 


The  following  statistical  diagram  shows  the  relative  product  of 
coal  by  the  several  nations  of  the  world: 


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TREATISE  ON  COKE 


*ofc     K; 


Peat— Turf 


The  Coal  Periods. — The  columnar  section  shows  the  places  of 
the  coal  among  the  rocks.  While  there  were  three  periods  of 
greatest  deposit,  the  evidence  in  the  remains  of  plants  from  the 
Laurentian  to  the  Tertiary  shows  that  plant  life,  in  greater  or 

less  degree  of  development,  ac- 
companied all  the  sedimentary 
deposits. 

The  remains  of  this  vegetable 
growth  are  found  in  the  Lauren- 
tian in  the  mineral  graphite, 
which  is  usually  associated  with 
folded  and  flexed  strata. 

In  the  eastern  part  of  the 
United  States  and  in  the  lower 
coal  measures,  which  are  also 
greatly  compressed  and  flexed, 
anthracite  coal  is  the  product  of 
this  old-age  flora.  Westward,  in 
the  Carboniferous  period,  under 
modified  conditions  of  rock  flex- 
ure, the  rich  bituminous  coals  are 
Comanche  Group  the  crystallized  remains  of  the 
luxuriant  flora  of  this  epoch. 
Farther  westward,  in  the  Jurassic, 
Cretaceous,  and  Tertiary  periods, 
bituminous  and  lignite  coals  are 
found,  as  the  results  of  the  recur- 
rences of  the  periods  of  the  coal- 
making  flora. 

The  more  recent  vegetable 
deposits  found  in  the  peat  or  turf 
bogs  afford  interesting  and  sug- 
gestive examples  of  the  genesis  of 
coal,  although  the  flora  exhibits 
newer  forms  and  conditions  from 
the  old-time  periods  of  the  coal- 
making  plants. 

An  example  of  the  mode  of 
bog  or  turf  deposit,  as  it  is  being 
accumulated  at  present,  is  seen 
on  the  line  of  the  N.  N.  &  W.  Rail- 
way, in  Newfoundland.  These 
deposits  occur  at  intervals  along 
the  line  of  this  railway  and  con- 
sist of  a  series  of  bogs  in  which 
a  growth  of  moss  and  other 
swamp  plants  is  accumulating. 
Under  the  cold  and  foggy  climate 


Coal  Lignites 


Laramie  Series 
Coal 


Dakota  Group 


Coal 


Permian 


Coal  Measures 


Upper  Silurian 


Lower  Silurian 


Primordial 


Huronian 


Laurentian 


SECTION  SHOWING  THE  PLACES  OP  COAL  IN 
THE  ROCKS — LE  CONTE 


TREATISE  ON  COKE  5 

and  with  frequent  drizzling  rains,  the  vegetable  mass  is  being 
altered  into  black  bog  in  the  bottom  and  brown  bog  above  this 
lowest  strata,  with  the  moss  and  heather  on  the  surface.  These 
deposits  are  4  to  6  feet  deep,  and  exhibit  all  the  processes  of 
growth,  with  the  graduations  from  brown  bog  down  to  the  dense 
black  bog  from  which  turf  is  made.  It  only  requires  a  further 
series  of  conditions  to  compress  and  crystallize  all  this  vegetable 
matter  into  true  coal. 


COAL  FIELDS  OF  THE  UNITED  STATES 

The  accompanying  geological  map  of  the  United  States  shows 
the  approximate  areas  and  localities,  as  far  as  determined,  of  the 
Carboniferous,  Triassic,  Cretaceous,  and  Tertiary  coals,  each  period 
being  distinguished  by  appropriate  cross-sectioning. 

As  this  map  is  designed  for  practical  use,  it  is  not  considered 
expedient  to  adopt,  at  this  time,  the  rather  intricate  classification 
of  the  great  coal  fields  used  by  the  United  States  Geological  Sur- 
vey in  some  of  its  latest  publications. 

The  Appalachian  field  is  uniform  in  the  quality  of  its  coal,  from 
New  York  state  to  Alabama.  It  does  not  .appear  necessary  to 
give  it  a  double  name,  Northern  and  Southern — the  same  is 
true  of  the  Western  fields.  These  are  distinctions  without  any 
economic  differences. 

The  table  of  outputs  of  coal  in  states  and  territories  has  also 
been  grouped  under  the  clear  classification  of  the  old  system. 

These  coal  fields  of  the  United  States  are  usually  classified 
under  eight  main  divisions  in  the  following  order: 

I.  The  Anthracite  Coal  Fields. — These  embrace  in  the  aggre- 
gate about  1,010  square  miles.  The  extreme  eastern  anthracite 
field,  lying  mainly  in  Rhode  Island,  with  its  north  end  resting  in 
Massachusetts,  contains  about  500  square  miles  of  coal  measures. 
It  affords  peculiar  varieties  of  anthracite  and  graphitic  coals,  but 
contributes  only  a  small  output  to  local  markets. 

In  Northeastern  Pennsylvania,  the  triple  anthracite  coal  fields 
cover  an  aggregate  area  of  485  square  miles.  These  three  regions — 
the  Schuylkill,  the  Lehigh,  and  the  Wyoming — with  their  small 
annexes,  contain  beds  of  pure,  glassy,  anthracite  coal,  with  thick- 
ness of  seams  from  3  feet  to  60  feet.  The  total  output  of  these 
fields  during  the  year  1901  was  67,471,667  net  tons,  valued  at 
$112,504,020.  The  small  anthracite  field  in  Sullivan  County, 
Pennsylvania,  with  detached  patches  of  anthracite  in  Maryland, 
West  Virginia,  Colorado,  and  New  Mexico,  cover  an  aggregate  area 
of  25  square  miles. 

All  the  above  coals  •  are  found  in  the  regular  Carboniferous 
measures.  Anthracite  coal  is  heavily  compressed  natural  coke. 


TREATISE  ON  COKE 


The  elementary  composition  of  the  coals  in  the  anthracite  fields 
will  be  readily  seen  from  the  average  proximate  analysis  of  each 
section  given  below: 


ANALYSES  OF  ANTHRACITE 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Rhode  Island  
Massachusetts  

8.36 

2.05 

6.09 
4.99 

73.23 
76.96 

11.68 
15.44 

.64 
.56 

Pennsylvania  

2.98 

3.38 

87.13 

5.86 

.65 

Colorado  

3.42 

8.76 

78.87 

8.30 

.65 

II.  The  Atlantic  Coast  Triassic  Coal  Fields. — These  detached 
coal  fields  are  found  midway  between  the  Blue  Ridge  Mountains 
and  the  Atlantic  Ocean.  They  consist  of  the  Richmond  and 
Farmville  basins  in  Virginia,  and  the  Dan  River  and  Deep  River 
basins  in  North  Carolina.  The  aggregate  area  of  these  coal  fields 
is  660  square  miles. 

The  coal  in  the  Richmond  basin  is  bituminous,  and,  when  prop- 
erly treated,  makes  a  medium  quality  of  coke.  The  natural  coke  or 
carbonite  of  this  basin  is  a  peculiar  product,  as  some  sections  of  the 
coal  beds  have  been  coked  by  the  intrusion  of  diabase  dikes,  which 
follow  the  floor  or  roof  of  the  coal  beds,  producing  a  light  cellular  coke. 

The  coal  beds  in  the  Farmville  field  are  of  moderate  thickness 
and  much  disturbed  by  flexures  and  faults. 

The  Deep  River  and  Dan  River  fields  are  found  under  similar 
conditions  to  the  Farmville.  The  Dan  River  region  is  regarded 
more  hopefully  than  the  others. 

ANALYSES  OF  TRIASSIC  COALS  AND  COKES 


Locality 

Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Remarks 

Richmond  basin  1 
north  side  .  .  .  .  / 

24.57 

62.39 

13.04 

Averages 

Richmond  basin,  j 
south  side.  .  .  .  / 

34.25 

62.97 

3.24 

Averages 

Natural  Coke.  .    .  . 

1.66 

18.35 

67.13 

12.86 

4.70 

Natural  Coke.  .    .  . 

9.98 

80.30 

9.72 

Farmville  

1.43 

28.28 

53.60 

11.81 

4.67 

Averages 

Dan  River  

.36 

17.99 

55.47 

26.16 

5.56 

Dan  River.  ... 

13.50 

76.56 

12.00 

Deep  River  .  .  .  .  j 
Cumnock  Mine  .  / 

1.216 

32.914 

57.36 

6.58 

1.93 

f  Main 
I  bench 

III.     The  Appalachian  Coal  Field. — The  Appalachian  coal  field  is 
the  largest  and  most  liberally  endowed  coal  field  in  the  world.     It 


8 


TREATISE  ON  COKE 


lies  along  the  western  side  of  the  Appalachian  mountains,  and  has 
a  general  trend  southwestwards.  The  northern  end,  with  its  ter- 
minal fingers  and  outlying  coal  fields,  rests  in  Northwestern  Penn- 
sylvania, nearly  touching  the  New  York  state  line.  The  southern 
end  rests  in  the  state  of  Alabama.  It  has  a  length  somewhat  over 
800  miles,  with  a  width  of  30  to  180  miles,  and  covers,  in  its  broad 
southwestward  course,  portions  of  the  states  of  Pennsylvania,  Ohio, 
Maryland,  Virginia,  West  Virginia,  Kentucky,  Tennessee,  and 
Alabama.  The  general  trend  of  its  eastern  border  approximates 
to  a  conformity  with  the  shore  line  of  the  Atlantic  Ocean.  The 
coal  measures  belong  to  the  Carboniferous  proper  and  vary  in 
aggregate  thickness  from  a  few  hundred  feet  to  3,000  or  4,000  feet. 

There  are  two  groups  of  coal  beds  in  this  field — the  lower  and 
upper — which  are  associated  with  the  lower  and  upper  barren 
measures.  The  Pottsville,  or  Serai,  conglomerate  is  the  base  of 
these  coal  measures.  The  lower  coal  beds  embrace  a  thickness  of 
280  feet,  more  or  less.  The  lower  barren  measures  have  a  thick- 
ness of  600  feet.  The  upper  productive  coal  measures  have  a 
thickness  of  360  feet,  while  the  upper  barren,  or  capping,  measures 
are,  at  some  localities,  1,100  feet  thick.  This  great  coal  field, 
which  includes  an  area  of  59,370  square  miles,  affords  the  largest 
areas  producing  coal  for  the  manufacture  of  coke. 

The  general  structure  of  the  anthracite  and  Appalachian  coal 
fields  consists  in  a  series  of  rock  waves  and  flexures,  beginning 
in  billows  near  the  seaboard,  moderating  to  waves  in  the  middle 
Appalachians,  and  calming  to  mild  ripples  on  the  western  flank  of 
this  longitudinal  belt  of  some  300  miles  in  width. 

West  Virginia  is  credited  with  having  the  maximum  depth 
of  coal  measures.  The  coal  beds  vary  from  a  few  inches  to  10  feet  or 
more  in  thickness  and  the  percentage  of  coal  to  the  associated  rocks 
and  shales  is  usually  estimated  as  1  foot  of  coal  to  50  feet  of  slate 
and  rock  measures. 

It  is  impossible,  in  a  brief  table,  to  give  all  the  qualities  of  coals 
embraced  in  this  large  territory,  but  it  is  believed  that  the  following 
tabulated  analyses  will  give  the  general  averages : 

ANALYSES  OF  APPALACHIAN  BITUMINOUS  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Pennsylvania  —  East  .  . 

1.73 

23.89 

67.03 

6    69 

66 

Pennsylvania  —  West  
Ohio  

1.70 
1  58 

39.15 
41  86 

46.66 
51   44 

10.52 
5  12 

1.97 
2  64 

West  Virginia  —  East 

1  52 

19  81 

72  71 

5  20 

76 

West  Virginia  —  West.  . 

1  52 

37  86 

53  37 

6  03 

1   22 

Kentucky 

1  80 

33  00 

60  10 

5  10 

65 

Tennessee  
Alabama  .  . 

1.50 
1  65 

32.51 

32  48 

59.33 
60  15 

5.82 
4  82 

.84 
90 

TREATISE  ON  COKE 


9 


IV.  The  Northern  Coal  Field. — The  Michigan  coal  field,  in  the 
middle  of  the  state,  covers  an  area  of  7,500  square  miles.  This  coal 
basin  lies  in  a  rather  flat  country,  surrounded  by  higher  land. 
These  coal  measures  belong  to  the  true  Carboniferous  period.  The 
coal  seams  are  somewhat  irregular  in  character  and  continuity. 
During  recent  years,  considerable  mining  has  been  entered  upon. 
The  upper  coal  beds  afford  coking  coal,  the  lower  beds  of  coal 
are  non-coking. 

ANALYSES  OF  MICHIGAN  COALS 

(From  Alfred  C.  Lane) 


• 

Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Pere  Marquette,  No.  1  Saginaw.  .  .  . 
Jackson    New  Hope  mine  

10.15 
5.58 

33.14 

46.73 

53.95 

45.28 

2.76 
2.41 

1.10 
2.83 

Saginaw  Co     Verne 

5.82 

39.79 

45.15 

9.24 

3.83 

V.  The  Central  Coal  Field.— This  coal  field  of  46,000  square 
miles  lies  in  the  states  of  Illinois,  Indiana,  and  Western  Kentucky. 
It  contains  the  three  general  varieties  of  bituminous,  block,  and 
cannel  coals.  The  main  portions  of  the  coals  of  this  field  are 'rich  in 
bituminous  matter.  The  block  coal  of  Indiana  is  a  peculiar  fuel; 
in  coking,  its  volatile  matters  are  expelled,  leaving  the  normal 
structure  of  the  coal  intact,  and  in  this  condition  it  is  simply  a 
charred  coal. 

ANALYSES  OF  CENTRAL  FIELD  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Block 

2.10 

39.05 

55.20 

2.90 

.75 

Indiana  |  Bituminous 

2.98 

40.98 

50.70 

3.46 

1.88 

Illinois,  Jackson  County  .  .  . 
Kentucky  {^uminous.... 

2.08 
4.48 
1.46 

37.10 
32.22 
45  '.35 

52.17 
54.03 
45.80 

7.02 
7.90 
6.63 

1.63 
1.37 
.76 

During  recent  years,  the  Illinois  coals  have  been  mined  largely, 
and  under  careful  treatment  have  appreciated  in  market  value. 
Efforts  are  now  being  made  to  coke  some  of  the  coals  in  this  field, 
which,  with  the  improved  machinery  for  crushing,  classifying,  and 
washing,  afford  indications  of  moderate  success.  So  far,  however, 
the  efforts  at  coking  the  large  bed  of  coal  in  Southern  Illinois  have 
not  met  the  expectation  of  the  parties  in  Chicago  that  have  made 
a  series  of  experiments  testing  the  coking  properties  of  these  coals. 

VI.  Rocky  Mountain  Coal  Fields. — The  Rocky  Mountain  coal 
regions  cover  portions  of  the  Dakotas,  Montana,  Idaho,  Wyoming, 


10 


TREATISE  ON  COKE 


8 


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Coking 
Coking 
Bituminous 
Semibituminous 
Lignite 
Anthracite 

Lignite 
Bituminous 

Lignite 
Bituminous 
Anthracite 

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TREATISE  ON  COKE 


11 


Utah,  Colorado,  and  New  Mexico.  The  coal  fields  in  this  territory 
embrace  the  deposits  on  the  flanks  of  the  Rocky  Mountains,  the 
main  areas  of  coal,  developed  at  this  time,  being  found  on  the  east- 
ern side  of  these  mountains. 

The  qualities  of  these  coals  are  quite  varied,  including  the  Permo- 
Carboniferous,  the  Jura-Trias,  with  the  Laramie,  the  Cretaceous,  and 
the  Tertiary.  Some  of  these  coals  make  good  coke,  but  many  of 
them  will  not  fuse  in  a  coke  oven.  Several  of  the  beds  are  quite 
thick,  and  afford  valuable  fuel  for  generating  steam,  and  for  metal- 
lurgical, manufacturing,  and  domestic  uses. 

Within  the  past  decade,  the  United  States  government  officials 
have  investigated  and  thrown  much  favorable  light  on  these  fields, 
and  these  investigations,  together  with  private  enterprise,  have 
disclosed  the  increasing  value  of  these  great  coal  deposits. 

The  following  statement,  from  the  Twenty-second  Annual 
Report  of  the  United  States  Geological  Survey,  will  exhibit  the 
progress  in  coal  mining  and  coke  making  in  this  extensive  coal 
region  during  the  year  1901: 


State 

Coal  Produced 
Net  Tons 

Coke  Made 
Net  Tons 

Dakota.        .        .  .         

Montana  

1.396,081 

57,001 

Idaho  

^Wyoming 

4  485  374 

Utah 

1  322,614 

Colorado                                                      •. 

5,700,015 

671,303 

New  Mexico.         .  .                           

1,546,652 

41,643 

The  coal  measures  in  these  fields  cover  an  area  of  100,110  square 
miles  as  known  at  the  present  time,  but  future  explorations  and 
government  surveys  will  probably  increase  the  area. 

VII.  The  Western  Coal  Field. — The  western  coal  field  occupies 
the  southern  portion  of  the  state  of  Iowa,  the  southeastern  corner 
of  Nebraska,  the  northwestern  section  of  Missouri,  the  eastern  side 
of  Kansas,  passing  through  the  eastern  portion  of  the  Indian  Terri- 
tory and  resting  in  a  great  prong  in  the  middle  of  the  state  of 
Arkansas.  It  occupies  the  interior  plain  of  the  continent,  and 
has  an  area  of  99,800  square  miles  of  coal  measures. 

Extensive  mining  operations  are  carried  on  in  the  states  of  Iowa, 
Missouri,  and  Kansas,  and  in  the  Indian  Territory  where  recent 
explorations  have  developed  large  beds  of  coal  fairly  well  adapted 
to  the  manufacture  of  coke  In  the  states  of  Missouri  and  Kansas 
a  few  coking  plants  are  in  operation,  but  the  output  is  small.  In 
the  Indian  Territory,  several  coke  plants  are  in  successful  operation, 
the  coke  being  marketed  mainly  in  Mexico. 


12 


TREATISE  ON  COKE 
ANALYSES  OF  WESTERN  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Iowa                                    .... 

3.00 

6.50 

3.25 

1.05 
1.79 
1.02 
1.05 

38.25 
37.71 

40.96 
19.04 
40.20 
10.49 
14.65 

48.50 

42.17 

43.98 
71.73 
51.79 
76.12 
76.11 

7.50 
10.56 

10.71 
7.53 
4.88 
9.96 
6.63 

2.75 

3.06 

1.10 
.65 
1.34 
2.41 
1.56 

Missouri  

Nebraska  
Kansas  

Indian  Territory{^t:;; 
f  East  .  . 

Arkansas{West  

The  Texas  coal  field  belongs,  by  geographical  position,  to  the 
Western  field.  Prof.  E.  T.  Dumble,  formerly  State  Geologist,  in 
regard  to  these  lignites,  states:  "It  should,  however,  be  plainly 
understood  in  the  beginning,  that  the  brown  coals  of  Texas  will 
be  found  to  differ  very  widely  in  quality,  and  it  will  require 
analysis  of  each  deposit  to  tell  with  certainty  for  what  purpose  it 
is  best  adapted." 

ANALYSES  OF  BROWN  COALS  OF  TEXAS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Stevens  . 

10   00 

5  81 

48    46 

4   20 

1    53 

Eagle  Pass  . 

5.27 

37.48 

44  46 

10  22 

2  57 

Laredo  

2.00 

50.05 

39.10 

7  35 

1   50 

Bowie  County  

10.32 

76.35 

11.53 

1.45 

.35 

VIII.  The  Pacific  Coast  Coal  Fields.— The  Pacific  Coast  coal 
fields  embrace  a  number  of  detached  fields  in  the  states  of  Washing- 
ton, Oregon,  California,  and  Alaska.  These  coals  are  nearly  all  of 
the  Tertiary  age,  and  of  the  general  character  of  lignites.  The 
fields  are  of  limited  extent  and  widely  separated.  Their  products 
of  coal  and  coke  during  the  year  1901  were  as  follows: 


State 

Coal 
Net  Tons 

Coke 
Net  Tons 

Washington  

2  578  217 

49,197 

Oregon  

69011 

California  and  Alaska  

151,709 

The  geological  survey  of  these  fields  is  not  yet  complete.  It  is 
estimated,  from  what  is  known,  that  the  aggregate  area  of  these 
coal  fields  is  about  30,000  square  miles.  The  coal  is  mainly  of  the 
Eocene  age,  ranging  from  lignite  to  coking  coal. 


TREATISE  ON  COKE 


13 


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14 


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16 


TREATISE  ON  COKE 


In  Western  Washington,  some  seams  of  bituminous  coal  have 
recently  been  found  which  are  reported  as  well  adapted  for  the 
manufacture  of  coke;  and,  also,  in  Eastern  Washington  coking  coals 
have  been  developed. 

In  addition  to  these  fusing  or  coking  coals  found  in  this  field, 
the  chief  varieties  of  coals  are  valuable  for  industrial  and  domestic 
purposes. 

ANALYSES  OF  PACIFIC  COAST  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Washington  < 
Oregon  j 

2.36 
1.74 
20.00 

41.91 
30.70 
32.50 

48.65 

58.30 
41.98 

7.08 
9.26 
5.34 

California                                I 

1.53 
15.50 

38.33 
40.00 

44.94 
29.50 

10.71 
15.00 

4.49 

Alaska.    .  .  . 

18.08 
2.57 

39.30 
55  44 

35.61 
29  75 

7.01 
12  24 

88 

Evidently  there  is  a  large  area  of  the  Washington  coals  that, 
with  careful  preparation  in  crushing  and  washing,  will  make  excel- 
lent coke. 


COAL  FIELDS  OF  CANADA 

In  the  Dominion  of  Canada,  the  coal  deposits  have  been  classed 
in  three  sections: 

I.  The  Nova  Scotia  and  New  Brunswick  Fields. — These  lie  in 
the  Bay  of  Fundy,  and  have  a  desirable  location  for  marketing  their 
coal  on  the  Atlantic  seaboard.  The  coal  is  similar  in  quality  to  the 
coal  of  the  eastern  Appalachian  field.  The  coal  measures  are  13,000 
feet  thick,  and  the  aggregate  area  of  the  two  fields  is  reported  to  be 
18,000  square  miles. 

The  coal  belongs  to  the  Carboniferous  period,  and  is  used  for 
coking,  for  iron  manufacture,  and  for  all  industrial  and  domestic 
purposes. 

AVERAGE  ANALYSES  OF  NOVA  SCOTIA  AND  NEW  BRUNSWICK  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Pictoti 

1.20 
1.30 
1.10 
1.15 
1.10 

.50 

28.43 

37.50 
29.10 
25.61 
25.83 
57.10 

56.98 
56.00 
56.60 
60.73 
67.57 
42.40 

13.39 
5.20 
13.20 
12.51 
5.50 
.27 

Joggins  

Springhill  
Nova  Scotia  

Cape  Breton 

Albertite 

TREATISE  ON  COKE 


17 


II.  British  Columbia  and  Vancouver's  Island  Field. — The  coal 
measures  in  this  section  belong  to  the  Cretaceous  and  Tertiary  for- 
mations. The  coal  beds  are  large  and  the  quality  is  mainly  of  the 
better  class  of  such  coals.  The  amount  of  pressure  appears  to  be 
the  important  factor  in  determining  the  physical  properties  of  these 
coals,  and  consequently  of  their  value. 


ANALYSES  OF  BRITISH  COLUMBIA  AND  VANCOUVER  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

a  Non-coking 

15   75 

35  40 

41   45 

7.40 

b  Non-coking 

8  60 

35.51 

46.84 

9.05 

c  Good  coking 

36  .  065 

36  .  065 

61.29 

2.645 

McKay   No    14  

4..  01 

40.07 

51.82 

4.10 

Nanainio  ... 

1.70 

38.10 

48.48 

11.72 

III.     Eastern  Rocky  Mountain  and  Great  Plains  Field. — In  the 

great  plains  east  of  the  Rocky  Mountains,  and  in  the  eastern  flank- 
ing ridges,  the  coal  occurs  in  the  Cretaceous  formation,  including 
the  Laramie.  This  field  is  simply  the  extension,  northwards,  of  the 
lignite  and  brown  coal  measures  of  the  Rocky  Mountain  series  of  the 
United  States.  Some  of  these  coals  can  be  used  for  the  manufac- 
ture of  coke,  but  the  larger  proportion  goes  to  other  uses. 


ANALYSES  OF  ROCKY  MOUNTAIN  AND  GREAT  PLAINS  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

a  Non-coking.  .  .    .         ... 

20   54 

33  26 

41    15 

5   05 

b  Non-coking  

10.35 

34.40 

39.61 

15  64 

c  Non-coking  
d  Good  coking  

6.50 
4.41 

38.04 
40.32 

47.91 
48.27 

7.55 
7.00 

e  Western  anthracite  

.71 

10.79 

80.93 

7.57 

MEXICAN  COAL  FIELDS 

The  Mexican  coals  are  evidently  found  in  the  Cretaceous  or  Ter- 
tiary formations,  probably  in  the  former.  They  appear  to  be 
related  in  part  to  the  Texas  coals. 

The  Coahuila  Coal  Company,  near  Sabinas,  on  the  Mexican 
International  Railroad,  mine  coal  and  make  a  fair  quality  of  coke 
from  washed  Alamo  coal.  The  analvses  are  as  follows: 


18 


TREATISE  ON  COKE 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Coal     .             

20.35 

20.35 

67.64 

12.01 

86 

Coke  

1  35 

1.35 

83.80 

14.85 

1.08 

The  coke  is  used  mainly  in  smelting  establishments,  and  com- 
mands a  ready  sale.  It  is  a  fairly  good  coke,  approximating  in  its 
physical  properties  the  Tioga  coke  of  Pennsylvania.  The  coal  from 
which  it  is  made  requires  careful  and  intelligent  work  in  preparing 
it  for  the  coke  oven. 


CHAPTER  II 


THE   FORMATION   AND    CHEMICAL   PROPERTIES   OF   COAL 

Formation  of  Coal. — The  genesis  of  coal  has  now  been  clearly 
shown  to  have  been  in  the  swamp  flora  of  the  old-time  periods  of 
coal  making,  and  the  vegetable  origin  of  coal  is  therefore  no  longer 
questioned.  This  conclusion  has  been  reached  from  the  evidences 
of  the  remains  of  plants  of  these  Carboniferous  periods  in  imme- 
diate connection  with  the  coal  beds;  by  the  physical  structure  of 
the  coal,  disclosing  the  anatomy  of  the  several .  families  of  plants 
from  which  it  was  made;  and  from  chemical  analyses  tracing  its 
derivation  from  vegetable  matter. 

Coal,  therefore,  was  made  from  vegetable  and  woody  matter, 
which  grew  luxuriantly  in  broad  and  extended  marshes  in  the  old- 
age  times,  when  the  Appalachian  sea  covered  most  of  the  continent 
of  North  America.  This  vegetable  matter,  in  its  decay  and  fall, 
was  entombed  in  the  waters  of  these  swamps,  which  kept  it  from 
the  atmosphere,  and  thus  preserved  it  from  oxidation  or  waste. 

It  is  also  evident  that  'the  more  thoroughly  this  vegetable 
matter  was  submerged,  the  more  .perfectly  the  resulting  coal  was 
bituminized.  This  immersion  in  water  contributed  a  very  impor- 
tant element  in  the  formation  of  the  more  highly  bituminous  and 
coking  coals. 

The  deposit  of  carbonaceous  matter  was  followed  by  a  covering 
of  slates,  shales,  sandstones,  or  limestone  deposits,  which  afforded 
different  degrees  of  pressure  on  the  entombed  vegetable  matter, 
and  assisted  in  the  subsequent  crystallization  of  the  coal. 

The  flora  of  the  coal-making  periods  consisted  mainly  of  the 
large  families  of  tree  ferns,  Sigillaria,  Calamites,  and  their  allies — 
soft,  rapid-growing  plants,  with  jointed  stems  and  broad  spear- 
shaped  leaves,  which  fell  in  frequent  showers  into  the  waters  of 
these  marshes.  These,  with  the  mosses,  ground  ferns,  and  other 
plants,  composed  the  vegetable  mass  that  made  the  coal. 

The  atmosphere  of  the  coal -flora  periods  was  in  large  part  com- 
posed of  carbon  dioxide,  which  contributed  largely  to  the  heat, 
and  furnished  plant  food  for  the  luxuriant  growth  of  the  flora. 

But  complementary  to  all  these  conditions  of  climate,  rapid 
vegetable  growth,  and  swamp  lagoons  to  preserve  it  for  coal  making, 
great  movements  in  the  earth  crust  were  of  prime  necessity  in 

2  19 


20  TREATISE  ON  COKE 

affording  definite  time  for  the  accumulation  of  vegetable  matter  to 
make  coal  beds  of  useful  thickness  and  to  entomb  them  for  the 
use  of  the  coming  age  of  man. 

The  broad  geological  law  has  been  fully  established,  that  all 
continents  have  been  formed  beneath  the  sea  and  then  emerged 
from  it.  Not  only  this,  but  also  from  the  way  the  several  sedimen- 
tary formations  rest  upon  each  other,  it  is  evident  that  the  land 
has  been  alternately  emerged  and  submerged  many  times  in  the 
process  of  its  formation.  These  movements  of  the  submergence 
and  emergence,  during  the  formation  of  the  coal  measures,  are  in 
entire  harmony  with  the  laws  governing  the  formation  of  all  the 
sedimentary  deposits. 

It  will  also  be  readily  understood  that  in  the  coal-making 
periods,  under  varied  conditions  and  extended  time,  a  variety  of 
coals  have  been  made,  with  different  degrees  of  purity,  and  with 
varied  ratios  of  fixed  to  volatile  matters.  These  changes  have 
also  been  influenced  by  the  subsequent  movements  in  flexing  the 
strata,  producing  the  debituminization  of  the  coal  in  greater  or 
less  degrees.  In  the  greatly  flexed  and  folded  regions  of  the  coal 
fields,  local  causes  have  contributed  to  carry  the  change  still 
further,  producing  anthracite  coal  from  the  evolved  heat  in  these 
movements.  Where  this  metamorphosis  has  been  carried  still 
further,  the  ultimate  is  produced  in  graphite  or  black  lead. 

It  is  well  known  that  all  vegetable  tissue  contains  some  incom- 
bustible matter,  which  is  designated  as  "ash "in  coal.  It  ranges 
from  1  or  2  per  cent,  to  5,  10,  or  more  per  cent,  in  the  usual  varieties 
of  coals,  t  When  coal  contains  more  than  5  per  cent,  of  ash,  it  is 
evidence  of  the  deposit  of  mud  from  other  sources  than  the  vege- 
table matter  making  the  coal.  This  additional  impurity  has  come 
into  coal  from  sediment  in  the  waters  of  the  marshes  and  from  the 
fine  muds  composing  the  roof  of  the  coal  bed.  The  ratio  of  this 
fine  mud  or  slate  impurity  in  coal  can  increase  until  the  former 
predominates,  causing  the  product  to  lose  its  rank  among  the  use- 
ful family  of  coals. 

The  usual  law,  with  some  exceptions,  is  that  this  slate  impurity 
in  coal  carries  with  it  iron  pyrites,  FeS2  (a  compound  of  sulphur 
and  iron),  so  that  the  volumes  of  these  undesirable  impurities  are 
usually  found  in  a  varying  proportion  to  the  amount  of  ash  in  the 
coal,  increasing  generally  as  the  ash  increases.  But  there  are 
exceptions  to  this  law. 

Varieties  of  Coal. — It  is  assumed  that  what  is  now  ranked  as 
bituminous  coal  represents  the  normal  condition  of  all  true  coal 
prior  to  the  subsequent  changes  by  the  agencies  of  heat. 

Fig.  1  illustrates,  in  a  general  way,  the  chemical  and  physical 
changes  in  the  formation  of  the  several  varieties  of  coal,  from  its 
organic  constituents  in  plant  tissue  to  the  last  result  in  graphitic 
carbon. 


TREATISE  ON  COKE 


21 


Prof.  Joseph  Le  Conte  has  given  the  approximate  composition 
of  these  typical  varieties  of  bituminous  coal  and  graphite,  and  has 


10       20       30       40       50       60       70       80       90   100 


Cellulose.  .  . 
Peat . . 


Lignites  or  brown 
coal 

Bituminous.  . 


Semibituminous .  . 
Semianthracite .  .  . 

Anthracite 

Graphite 


FIG.  1.     DIAGRAM  SHOWING  GENETIC  RELATIONS  OF  THE 
CARBON  MINERALS,  AFTER  PROF.  J.  S.  NEWBERRY 


constructed  the  following  chemical  formulas  showing  the  changes 
under  which  they  were  formed: 


Vegetable  matter,  cellulose 

Subtract  9  CO2,  3  CH4,  11  H2O  ........  C12H34O2 

And  there  remains  ...................  C24//26O 

Vegetable  matter 

Subtract  7  CO2,  3  CH4,  14  H2O 

And  there  remains 


Vegetable  matter C3 

Subtract  10  CO2,  10  C7f4,  10  H2O C2 

And  there  remains.  .  .  .C, 


cannel 


=  bituminous  coal 


=  graphite 


The  table  on  the  following  page  exhibits  the  principal  elements 
of  the  genesis  and  varieties  of  coals. 

From  this  table  will  be  noted  the  gradual  changes  effected 
during  the  lapse  of  time,  in  which  plant  tissue  has  been  subjected  to 
natural  distillation.  In  the  western  coal  fields  we  have  impressive 


*The  composition  of  wood  timber  is  usually  given  as  about  C12HISOS. 
I  have  taken  the  formula  of  cellulose  instead,  viz.,  C6HWO5;  or,  taking  six 
equivalents  for  convenience  of  calculation,  C^H^f)^.  I  believe  this  to  be 
much  nearer  the  composition  of  the  vegetable  matter  of  the  coal  period 
than  is  the  formula  of  hardwood  like  oak  or  beech.  All  the  results  may  be 
worked  out,  however,  with  equal  ease  by  the  use  of  either  formula  for  vege- 
table matter. 


22 


TREATISE  ON  COKE 


examples  of  such  changes,  in  the  localities  of  trap  outbursts,  altering 
the  Cretaceous  or  Tertiary  coals  to  good  bituminous  and  anthracite 
varieties.  To  what  extent  this  metamorphism  has  affected  many 
localities  of  far  western  coals  that  are  now  profitably  used  in  the 
manufacture  of  coke,  is  not  clearly  made  out.  It  is  submitted  by 
some  observers,  that  the  chief  element  that  has  altered  these  western 
coals  into  the  many  varying  grades  in  which  they  are  found  to  exist, 
is  the  pressure  from  upheaval  and  flexure. 

PRINCIPAL  ELEMENTS  OF  THE  GENESIS  AND  VARIETIES  OF  COALS 


Names 

Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Cellulose  

55.36 

41.44 

3.00 

.20 

Peat  

24.20 

27.00 

45.30 

3.30 

.20 

Lignite  
Brown  coal 

27.90 
29  06 

66.09 
66  31 

4.00 
2  27 

1.00 
2  36 

Cannel    

2.10 

14.99 

68.13 

12.30 

2.48 

Albertite  
Bituminous   . 

1.78 

13.68 
35  36 

86.04 
58  29 

.10 
3  89 

trace 
68 

trace 

Semibituminous  .  . 
Semianthracite  .  .  . 
Anthracite  
Graphite  .  ,  

1.20 
2.27 
2.98 

23.89 
8.83 
3.38 

67.56 

78.83 
87.13 
99.00 

6.69 
9.39 
5.86 
1.00 

.66 
.68 
.65' 

.   .005 

the  evident   cause  of  these 
in  the  neighborhood  of  trap 


It  will  be  noted,  however,  that 
changes  in  the  varieties  of  coals, 
dikes  or  outbursts,  with  the  resultant  heat,  is  easily  understood, 
but  in  large  areas  of  coal  deposits,  without  any  evidence  of  erup- 
tive heat,  the  cause  must  be  sought  in  other  conditions. 

The  rich  bituminous  coals  of  Western  Pennsylvania,  the  semi- 
bituminous  coals  on  the  eastern  flank  of  the  Alleghany  field,  the 
pure,  glassy  anthracite  of  the  eastern  fields,  and  the  graphitic  anthra- 
cite of  the  state  of  Rhode  Island  all  belong  to  the  same  age — the 
true  Carboniferous  period.  From  the  analyses  of  these  coals,  it  will 
readily  appear  that  the  largest  evolved  products  of  natural  distilla- 
tion occurred  in  Rhode  Island,  moderating  in  its  action,  westwardly, 
until  the  normal  condition  of  bituminous  coal  is  found  in  Western 
Pennsylvania  and  Ohio.  While  there  may  exist  some  conflict  of 
opinion  as  to  the  cause  of  this  debituminization  of  coal  eastward, 
the  fact  that  such  has  been  consummated  is  not  in  dispute. 

In  considering  the  cause  or  causes  that  have  produced  the 
various  conditions  of  coals,  the  fact  is  quite  evident  that  all  the 
anthracites  in  Rhode  Island  and  in  Eastern  Pennsylvania  are  found 
in  sections  that  have  been  violently  flexed  and  tilted.  This  work 
of  folding  and  flexing  the  eastern  flank  of  the  continent  must  have 
been  accompanied  with  a  large  amount  of  evolved  heat,  as  the 
pushing  forces  exerted  must  have  been  enormous.  As  all  the 


TREATISE  ON  COKE  23 

measures  in  these  sections  have  been  baked  with  heat  in  about  the 
proportion  to  the  violence  of  the  disturbance  in  each  locality,  it  is 
evident  that  the  cause  or  causes  have  been  as  extensive  as  the 
results.  Hence,  it  has  been  inferred  that  the  heat  evolved  in  the 
flexing  of  the  measures,  combined  with  moisture  and  pressure, 
have  been  the  chief  agents  in  producing  the  conditions  that  have 
made  the  several  varieties  of  coals — anthracite,  semianthracite, 
and  bituminous. 

The  origin  of  this  dynamic  or  folding  force  evidently  had  its 
source  mainly  from  a  cooling  globe.  The  rigidity  of  the  rock  belt 
along  the  Atlantic  Ocean  seaboard  confined  the  main  body  of  this 
force  to  the  softer  inland  crust,  the  latter  being  crushed  and  flexed 
in  proportion  to  its  proximity  to  the  rigid  seaboard  belt,  beginning 
at  the  seaboard  with  the  largest  crust  waves,  moderating  into 
ripples,  and  as  Ohio  is  reached,  the  measures  are  nearly  horizontal. 
The  heat  evolved  in  these  great  crust  movements  altered  the 
eastern  coals  into  graphites,  anthracites,  and  semianthracites,  the 
coals  regaining  their  normal  condition  westward  beyond  this  region 
of  intense  disturbance. 

This  general  law  of  the  bituminization  of  coal  westward  has 
some  slight  exceptions.  At  the  summit  of  the  Alleghany  Moun- 
tains, at  Bennington,  the  coal  contains  23  per  cent,  of  volatile  matter, 
while  an  exceptional  belt  at  Johnstown,  26  miles  westward,  con- 
tains less  than  20  per  cent,  of  hydrogenous  matter.  From  Johns- 
town westward,  the  increase  of  volatile  matter  is  quite  regular 
until  the  maximum  belt  of  the  normal  bituminous  coal  is  reached 
in  Western  Pennsylvania  and  Ohio. 

The  coals  of  the  eastern  anthracite  fields  have  been  thoroughly 
coked  under  immense  pressure,  making  this  natural  coke  too  dense 
for  the  best  results  in  blast-furnace  operations.  This  undesirable 
physical  condition  of  extreme  density  will  be  fully  considered  later. 

The  manufacturer  of  coke  can,  therefore,  intelligently  consider 
the  qualities  of  the  coals  in  the  Appalachian  and  western  fields  for 
use  in  making  coke.  As  the  dynamic  force  that  flexed  and  folded 
the  eastern  side  of  the  North  American  continent  exerted  its  greatest 
force  at  the  east,  diminishing  gradually  westward,  the  evidence  of 
the  action  of  the  diffused  heat  from  these  movements  is  seen  in  its 
effect  in  the  hard,  dry  anthracite  coals  of  Pennsylvania  and  Rhode 
Island,  the  dry  semibituminous  coals  of  Broad  Top  and  Cumber- 
land, with  the  increase  of  bituminization  of  the  coals  westward, 
until  the  normal  undisturbed  condition  is  reached  in  the  great  cen- 
tral plain  of  the  continent. 

The  table  on  the  following  page  gives  the  composition  of  the 
typical  varieties  of  coals,  from  Rhode  Island  to  Iowa. 

It  is  also  of  interest  to  consider  the  irregular  curved  lines  of  the 
eastern  escarpment  of  the  great  Appalachian  coal  field,  with  the 
deeply  curved  indents  in  Pennsylvania  and  Tennessee,  displaying 
the  immense  forces  that  have  flexed  and  pushed  back  bodily  these 


24 


TREATISE  ON  COKE 


portions  of  the  field,  with  measures  8  to  9  miles  thick.  In  the  sub- 
sequent erosion,  Tennessee  and  Alabama  suffered  most,  having  had 
the  dryer  sections  of  their  coals  carried  away  and  leaving  the  more 
western  sections,  with  their  increased  volumes  of  volatile  matter, 
for  the  manufacture  of  coke. 

TABLE  EXHIBITING  THE  DEBITUMINIZATION  OF  COALS— EASTWARD 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Iowa       

1.40 

41.40 

48.50 

7.50 

1    20 

Illinois  

1.25 

41.85 

48.90 

7.00 

1.00 

Indiana  

1.10 

37.06 

57.59 

3.50 

.75 

Ohio  

2.70 

33.49 

56.90 

5.99 

.92 

Pennsylvania 
Pittsburg 

1  28 

38  10 

54  39 

5  44 

79 

Connellsville  
Johnstown 

1.25 
1  03 

31.79 
16  49 

59.80 
73  84 

7.16 
7.97 

.60 
1  97 

Bennington  
Maryland,  Cumberland.  .  .  . 
Pennsylvania 
Semianthracite     

1.20 
.89 

1.25 

23.33 
15.52 

9.60 

69.02 
74.29 

81.30 

5.69 
8.59 

6.90 

.76 
.71 

.85 

Anthracite  

1.35 

3.45 

89.06 

5.81 

.30 

Rhode  Island,  Graphite 
Anthracite  

1.18 

3.80 

85.70 

8.52 

.80 

It  has  been  noted  that  in  the  meridional  sections  of  this  coal 
field,  if  not  in  all  fields,  the  qualities  of  the  coal  in  the  several  beds 
approximate  very  closely  in  their  chemical  composition;  so  that  if 
a  good  coking  coal  in  found  in  any  of  the  beds  in  a  special  section, 
all  of  its  associated  beds,  above  or  beneath,  will  probably  afford 
similar  good  results  in  coking. 


COMPOSITION  OF  COKING  COALS 

While  it  is  not  yet  clearly  determined  why  one  coal  will  fuse  in 
the  coke  oven  and  make  good  coke,  and  another  of  very  similar 
chemical  composition  will  not  fuse  in  coking,  yet,  in  the  Appa- 
lachian field,  it  has  been  found  reasonably  sure  that  coals,  approxi- 
mately equal  in  chemical  composition,  will  afford  similar  results  in 
the  process  of  coking. 

The  following  analyses  will  show  the  composition  of  the  standard 
typical  coking  coals  in  the  Appalachian  field. 

It  is  quite  remarkable  that  the  standard  coking  coal  of  the  Con- 
nellsville region  is  found  in  a  long,  narrow  synclinal  strip,  west  of 
the  Chestnut  Ridge.  It  affords  a  coal  with  an  average  chemical 
composition  between  the  rather  dry  coals  to  the  eastward  of  it 
and  the  too  bituminous  coals  westward. 


TREATISE  ON  COKE 


25 


ANALYSES  OF  STANDARD  APPALACHIAN  COKING  COALS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash    . 
Per  Cent. 

Sulphur 
Per  Cent. 

Pennsylvania 
Bennington  
Connellsville  

1.73 
1.26 

23.89 
31.79 

67.03 
59.79 

6.69 
7.16 

.66 
.60 

West  Virginia 
Monongah  

1.52 

37.96 

53.27 

6.03 

1.22 

Pocahontas              .... 

.69 

19.96 

73.02 

5.67 

.66 

Kentucky                          .... 

1.80 

32.34 

60.10 

5.10 

.66 

Tennessee                 

1.50 

32.51 

59.33 

5.82 

.84 

Alabama  

1.65 

32.48 

60.15 

4.82 

.90 

ANALYSES  OF  APPALACHIAN  COALS 


Coal  Fields 

Moisture 
at  212°  F. 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Second  Geological 
Survey  of 
Pennsylvania 

Cumberland  ...... 

.893 

15.522 

74.289 

9.296 

.714 

HHH,  p.  101 

Broad  Top  
Bennington  
Johnstown  
Blairsville  
Connellsville  
Greensburg  

.770 
1.200 
.720 
.920 
1.260 
1.020 

18.180 
23.680 
16.490 
24.360 
31.800 
33.500 

73.340 
68.170 
73.840 
62.220 
59.790 
61.340 

6.690 
5.730 
7.970 
7.590 
7.160 
3.280 

1.020 

.620 
1.970 
4.920 
.530 
.860 

Kelly  (D)1 
.      Miller  (B) 
C.  I.  Co.  Dr.  F. 
HHHH,  Unwshd 
C.  I.  Co.  Dr.  F. 
MM,  pp.  23,  24 

Irwin  
Armstrong  Co. 

1.410 
.960 

37.660 
38.200 

54.440 
52.030 

5.860 
5.140 

.640 
3.660 

MM,  p.  22 
MMM,  p.  56 

Whether  this  quality  of  coal  will  be  found  in  the  extensions  of 
this  strip  northeastward  and  southwestward,  paralleling  the  trend 
of  the  Appalachian  mountain  ranges,  is  yet  to  be  learned.  In 
other  words,  it  is  not  yet  known  what  were  the  ultimate  effects 
of  the  heat  diffused  during  the  period  of  the  flexing  of  the  coal 
measures  in  fixing  the  condition  of  the  quality  of  the  coal  as  regards 
leanness  or  richness  in  bituminous  matters. 

The  following  shows  the  average  composition  of  the  celebrated 
Durham  coking  coal,  England: 

PER  CENT. 

Moisture 90 

Volatile  matter 13 . 00 

Fixed  carbon 80 . 80 

Ash 4.39 

Sulphur .91 

It  is  very  remarkable  that  this  Durham  coal,  with  its  very  low 
volume  of  volatile  matter,  fuses  so  thoroughly  in  the  coke  oven 
(beehive)  and  produces  first-class  coke.  Such  a  well-determined 
result  adds  to  the  perplexity  of  the  investigation  to  determine  the 
reason  why  one  coal  will  coke  and  another  will  not. 


26 


TREATISE  ON  COKE 


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TREATISE  ON  COKE  27 

It  may  be  interesting  to  compare  the  composition  of  some  coking 
and  non-coking  coals  from  the  Carboniferous  measures  and  from  the 
Jura-Cretaceous  deposits. 

It  is  submitted  as  an  established  experience  that  the  approximate 
chemical  analyses  of  coals  will  not  disclose  their  coking  properties. 
It  is  therefore  evident  that  in  determining  the  type  of  coke  oven, 
with  the  proportions  of  its  chamber,  walls,  flues,  etc.,  the  only  safe 
plan  is  to  have  a  sufficient  quantity  of  coal  coked  in  the  several 
plans  of  ovens,  or  tested  in  some  reliable  experimental  plant.*  In 
this  respect  it  may  be  added  that  in  coking  the  coals  low  in  volatile 
combustible  matters  in  any  type  of  oven,  it  will  be  found  of  great 
benefit  to  break  the  coal  to  such  sizes  as  will  conduce  to  the  most 
economic  results  in  fixing  the  fusing  matters  in  the  initial  opera- 
tion of  coking.  With  coal  charged  into  the  oven  in  large  lumps,  it 
is  evident  that,  as  the  coking  begins  on  the  outside  and  moves 
slowly  into  the  interior  of  the  lumps,  the  gases  in  the  central  portion 
must  be  dissipated  in  more  or  less  volume,  depending  on  the  dry  ness 
of  the  coal  and  the  size  of  the  lumps. 

The  oven  will  also  be  required  to  be  kept  at  a  maximum  heat 
when  charging  the  coal  into  it.  With  the  disintegration  of  the  coal 
and  the  sustained  heat  of  the  oven,  the  small  volume  of  fusing 
matters  in  the  coal  can  be  promptly  fixed  in  the  coke  and  their 
dissipation  with  the  gases  prevented. 

As  the  Appalachian  coal  field  affords  the  greatest  supply  of 
coking  coals,  the  careful  study  of  the  approximate  analyses  of  these 
becomes  of  the  first  importance,  so  that  the  coke  oven  best  adapted 
for  the  several  varieties  of  coals  can  be  intelligently  selected. 

In  the  Appalachian  region,  the  analysis  of  the  coal  will,  in  most 
instances,  indicate  its  coking  properties,  but  westward  the  coals 
having  compositions  similar  to  good  coking  Appalachian  coals  fail 
to  fuse  in  the  coke  oven.  Pennsylvania,  Virginia,  West  Virginia, 
Kentucky,  Tennessee,  and  Alabama  have  been  especially  favored 
by  large  areas  of  good  coking  coals  in  this  great  field  of  59,370  square 
miles.  The  eastern  side  of  the  field  affords  the  coking  coals  best 
adapted  for  making  metallurgical  coke.  The  western  side  inherits 
too  much  bituminous  matter  to  assure  very  good  coke.  This  law 
is  shown  in  the  pitchy  coals  of  Ohio,  Indiana,  and  Illinois  and  by 
the  small  amount  of  coke  made  in  these  states. 

The  coals  of  Colorado,  Wyoming,  Montana,  and  the  other  north- 
western states,  belong  to  the  Jura-Trias  and  Laramie- Cretaceous 
measures,  and  are  independent  of  the  Appalachian  law  of  ratio  of 
volatile  hydrocarbons  to  fixed  carbon,  as  some  of  these  coals  can 
be  coked  readily  in  the  common  beehive  coke  oven,  as  at  the 


*There  are  reliable  establishments  in  the  United  States  for  testing  the 
washing  and  coking  properties  of  coals,  such  as  the  Link-Belt  Machinery 
Company,  Chicago,  Illinois;  Messrs.  Stein  &  Boericke,  Primes,  Delaware 
County,  Pennsylvania;  Roberts,  Schaefer  &  Company,  1275  Old  Colony 
Building,  Chicago,  Illinois;  and  the  Jeffrey  Mfg.  Co.,  Columbus,  Ohio. 


28  TREATISE  ON  COKE 

Trinidad  or  El  Moro,  the  Crested  Butte,  and  other  coke  works  of 
Colorado,  the  Cambria  Mining  Company,  of  Wyoming,  and  the 
Bozeman  and  Gardner  coke  works,  of  Montana.  On  the  other 
hand,  a  large  portion  of  these  northwestern  coals,  very  high  in 
hydrogenous  matters,  cannot  be  coked. 

It  is  slowly  becoming  evident  that  the  solution  of  the  coking 
or  non-coking  properties  of  coals  is  entirely  confined  to  the  relations 
and  volumes  of  the  elements  composing  the  volatile  combustible 
matters  of  the  coal.  The  moisture,  fixed  carbon,  ash,  and  sulphur 
may  differ  widely  in  good  coking  coals,  without  seriously  affecting 
their  coking  properties.  An  example  of  this  is  seen  in  the  very 
large  difference  existing  in  the  volumes  of  carbon  and  ash  in  two 
of  the  best-known  coking  coals,  Connellsville  and  Pocahontas; 
the  former  containing  59.79  per  cent,  of  fixed  carbon  and  the  latter 
72.70  per  cent.  The  ash  is  neutral,  exerting  no  influence  in  the 
fusing  of  coal  in  coking.  The  sulphur  and  phosphorus  come  under 
the  same  condition — they  are  simply  undesirable  elements  in  the 
metallurgical  coke. 

It  is  evident  that  large  differences  exist  in  the  volumes  of  the 
volatile  combustible  matters  in  the  coking  coals  of  the  Carbon- 
iferous age  in  the  Appalachian  field.  From  the  percentages  of 
volatile  combustible  matters  in  these  coals,  their  relative  coking 
properties  can  be  confidently  predicted.  These  percentages  of  vola- 
tile combustible  matter  for  a  coking  coal  range,  in  ordinary  coke 
ovens,  from  17  to  33  per  cent.;  with  retort  ovens  and  their  recu- 
perative and  regenerative  auxiliaries,  coals  inheriting  much  lower 
percentages  of  volatile  combustible  matters  can  be  coked.  The 
only  further  remark  in  this  connection  is,  that  in  coking  coals 
with  small  volumes  of  volatile  combustible  matter  affording  insuffi- 
cient heat  for  coking,  the  balance  of  the  heat  required  must  come 
from  the  fixed  carbon  of  the  coal. 

As  a  unit  of  carbon  affords  about  8,000  calories  of  heat,  while 
a  unit  of  hydrogen  affords  34,000  calories,  it  will  readily  appear  that 
coals  low  in  hydrogenous  matters  must  surrender,  in  the  ordinary 
open  ovens,  an  increased  volume  of  fixed  carbon  to  compensate  for 
the  deficiency  in  the  reduction  of  the  greater  heat-giving  hydrogen. 

The  loss  of  carbon  in  the  open  coke  ovens,  especially  in  coking 
the  dry  coals,  was  evidently  the  impelling  element  in  the  evolution 
of  coke  ovens,  and  in  developing  the  retort  or  closed  ovens  with  their 
auxiliary  recuperative  and  regenerative  appliances,  and  in  the 
utilization  of  the  gases  from  the  coking  coal  in  heating  the  oven 
chamber  and  saving  the  fixed  carbon  in  coking.  To  assure  sus- 
tained heat,  as  well  as  from  the  peculiar  construction  and  length 
of  these  retort  coke  ovens,  the  charges  of  coke  require  to  be  drawn 
by  mechanical  appliances. 

Returning  to  the  evidence  submitted,  locating  the  fusing  element 
or  elements  in  coals  of  the  Appalachian  age,  in  their  volatile  com- 
bustible matters,  it  was  shown  that  wide  differences  in  the  volumes 


TREATISE  ON  COKE  29 

of  fixed  carbon  could  exist  in  these  coals,  producing,  as  far  as  is  now 
known,  only  slight  modifications  in  their  coking  qualities. 

It  has  been  made  evident  by  practical  experience  that  in  the 
Appalachian  region  coals  containing  18  to  35  per  cent,  of  volatile 
combustible  matters  can  be  made,  with  proper  oven  treatment,  into 
good  coke.  Northwestward,  among  the  more  recent  deposits  of 
coals,  the  ratio  of  volatile  hydrocarbons  to  the  fixed  carbon  does 
not  indicate,  with  some  exceptions,  their  coking  properties,  as 
some  of  these  coals  inheriting  35  to  45  per  cent,  of  these  matters 
fail  to  fuse  in  any  type  of  coke  oven. 

It  has  been  noted  in  the  reports  of  the  United  States  Geological 
Survey  that  a  coal  found  in  Alaska,  and  containing  the  following 
elements,  could  not  be  coked: 

ALASKA  COAL  PER  CENT. 

Moisture,  212°  F 9.31 

Volatile  combustible  matters 40 . 85 

Fixed  Carbon 46 . 14 

Ash 3.70 


100.00 

.  But  in  the  Jura-Trias  and  Laramie-Cretaceous  coals,  this  Appa- 
lachian law  will  not,  as  a  general  rule,  be  found  reliable.  This 
will  be  seen  in  the  efforts  to  coke  the  large  samples  of  the  Sand- 
coulee  and  Belt  Mountain  coals  of  Montana.  In  comparing  their 
volumes  of  volatile  combustible  matters  with  the  Connellsville, 
their  close  relations  will  appear  as  follows: 

Connellsville,  Pennsylvania. .  .  31 . 80  per  cent,  of  volatile  combustible  matters 

Sandcoulee,  Montana 33 . 60  per  cent,  of  volatile  combustible  matters 

Belt  Mountain,  Montana. .....  28. 71  per  cent,  of  volatile  combustible  matters 

Connellsville  coal  is  the  standard  coking  coal  of  the  United 
States,  as  far  as  present  knowledge  has  disclosed;  the  coals  of  Sand- 
coulee  and  Belt  Mountain  are  mainly  non-coking. 

Tests  of  Sandcoulee  and  Belt  Mountain  Coals. — A  shipment  of 
coal  from  Sandcoulee,  Cascade  County,  Montana,  was  tested  at  the 
coke  works  of  the  Cambria  Iron  Company,  in  the  Connellsville  region, 
in  1889.  A  general  average  of  this  coal  from  a  bed  6  feet  6  inches 
to  8  feet  6  inches  thick,  showed  the  following  composition: 

PER  CENT. 

Moisture  at  212°  F 2. 260 

Fixed  carbon 54. 470 

Volatile  combustible  matters 33 . 600 

Ash 7.820 

Sulphur 1 . 850 

Phosphorus 009 

'  100.009 


30  TREATISE  ON  COKE 

The  two  benches  of  this  coal  bed  differed  in  quality ;  the  upper 
bench  affords  a  dull,  dry  coal,  the  lower  bench  is  brighter  and  more 
fusible  in  the  coke  oven.  The  coke  was  made  from  an  average  of 
both  benches — it  was  analyzed  as  follows: 

PER  CENT. 

Fixed  carbon 88 . 350 

Ash 10 . 850 

Sulphur 1.790 

Phosphorus 009 

100.009 

The  coke  exhibited  a  composite  structure;  the  coal  from  the 
upper  bench  did  not  fuse.  The  coking  operation  expelled  the  vola- 
tile matters,  leaving  the  normal  structure  of  the  pieces  of  coal 
unchanged — it  was  simply  charred  coal.  This  coal  received  pre- 
paratory treatment  in  various  ways  before  it  was  charged  into  the 
ovens — it  was  broken  into  small  pieces,  wetted,  etc.  The  operations 
of  coking  were  also  varied,  from  slow,  mild  heat  to  quick,  intense 
heat.  The  latter  method  gave  the  better  results.  The  coke  was 
made  in  the  beehive  ovens  with  great  care  and  by  expert  cokers. 
The  ultimate  decision  was  that,  while  the  Cretaceous  coal  is  well 
adapted  for  generating  steam  arid  for  domestic  and  other  uses,  it 
does  not  fuse  in  coking  so  as  to  produce  a  merchantable  coke. 

Another  sample  of  coal,  from  the  Belt  Mountain,  14  miles  south 
of  Sandcoulee,  Montana,  was  forwarded  to  Connellsville  for  test  in 
coking.  The  coal  bed  has  three  benches,  the  average  analysis  of 
these  is  as  follows: 

BELT  MOUNTAIN  COAL  PER  CENT. 

Moisture,  212°  F.  . . 2.980 

Volatile  combustible  matters 28 . 720 

Fixed  Carbon / 53 . 310 

Ash 13.340 

Sulphur 1 . 650 

Phosphorus 012 

100.000 

This  coai,  under  repeated  efforts  in  coking,  came  out  of  the 
oven  charred;  it  could  not  be  coked. 

On  the  other  side,  the  Trinidad  and  El  Moro  coal  of  Colorado, 
located  in  the  Cretaceous  measures,  and  holding  29.82  per  cent,  of 
volatile  combustible  matters,  affords  a  very  good  coke  in  beehive 
coke  ovens. 

This  important  inquiry,  as  to  the  composition  of  coals  that  will 
fuse  in  the  coke  oven,  has  elicited  and ,  continues  to  invite  much 
earnest  investigation  from  chemists,  and  while  some  approaches 
have  been  made  in  ascertaining  the  element  or  elements  that  pro- 
duce fusion  of  the  coal  in  coking,  yet  these  are  not  fully  assured  as 
general  principles  that  can  be  relied  on  for  universal  application. 

It  is  reported  that  some  German  chemists  have  made  tests  to 
ascertain  the  cause  of  the  coking  or  fusing  of  bituminous  coal  in  the 


TREATISE  ON  COKE  31 

coke  oven  under  distilling  heat,  the  conclusion  being  that  the  fusing 
property  of  the  coal  is  produced  by  its  richness  in  what  is  known 
as  disposable  hydrogen,  or  that  portion  which  is  in  excess  of  .the 
quantity  required  to  form  water  with  the  oxygen  present.  It  has 
been  shown  that  such  a  standard  for  the  fusing  quality  of  coal  does 
not  correspond  with  observed  results.  So  that  we  have  in  this  no 
sure  ground  for  such  determination. 

The  richness  of  the  coal  in  carbon  does  not  appear  to  govern  its 
fusing  capabilities,  the  fact  being  that  two  samples  of  coal  of  prac- 
tically equal  carbon  composition  will  be  found  to  behave  very 
differently  in  coking  in  the  ovens.  It  is  evident  that  if  the  genesis 
of  fusing  does  not  reside  in  the  surplus  hydrogen  or  fixed  carbon,  it 
certainly  does  not  lie  in  the  oxygen,  as  the  latter  affords  no  indica- 
tion of  the  physical  behavior  of  coal  in  the  retort  of  the  coke  oven. 

Fusibility  and  Coking  Properties. — The  following  extract  on  the 
fusibility  and  coking  property  of  coals  is  taken  from  the  American 
Manufacturer — the  author's  name  not  being  given: 

"It  has  been  long  known  that  the  property  of  coking  which 
belongs  to  many  coals — a  property  which  may  be  observed  in 
every  degree,  i.  e.,  from  a  weak  slagging  to  a  complete  fusion— is 
not  a  simple  or  partial  fusion,  and  the  fusion  of  mineral  coal  is 
accompanied  rather  by  a  fundamental  decomposition  of  the  same, 
just  as  is  the  case  when  sugar  is  subjected  to  a  high  heat,  whereby 
are  generated  gases  and  vapors  burning  with  a  more  or  less  lumi- 
nous flame  and  leaving  behind  them  a  fused  residue  consisting 
chiefly  of  carbon. 

"The  very  natural  supposition  that  the  fusibility  or  infusibility 
of  a  coal  must  always  stand  in  fixed  ratio  to  its  proportional  com- 
position is  not  at  all  borne  out  by  practice,  although  a  number  of 
isolated  cases  may  seem  to  give  it  support. 

''Percy  (Metallurgy)  found  the  following  percentages  of  hydro- 
gen, oxygen,  and  nitrogen  in  several  coking  and  non-coking  coals: 

NON-COKING  COKING  NON-COKING 

"l          JT     '  3        ~~T~~        5  6  7  8  9 

H 4.75    4.95      5.49      5.85      5.91      6.34      6.12      6.04      5.99 

O  and  N. . .5.28    7.36    10.86    14.52    18.07    21.15    21.13    22.15    23.42 

"The  following  excesses  of  hydrogen,  over  what  was  considered 
necessary  to  combine  with  the  oxygen  to  form  water,  were  found, 
that  is,  the  remaining  quantities  of  disposable  hydrogen: 

NON-COKING  COKING  NON-COKING 

1  2  '       '3  4        ~~F        '  6  7  8  9  ' 

H 4.09      3.53      4.13      4.04      3.65      3.70      3.47      3.22      3.06 

"The  property  of  coking  evidently  cannot  depend  on  this  dis- 
posable hydrogen,  since,  for  instance,  in  Nos.  1  and  4,  non-coking 
and  coking  coals  respectively,  it  is  very  nearly  the  same. 


32  TREATISE  ON  COKE 

'The  sum  of  hydrogen  and  oxygen  in  these  nine  coals  is: 
NON-COKING  COKING  NON-COKING 


10.03      11.81        16.35     20.37     23.98       27.49     27.35     28.59     29.41 

"From  this  it  might  be  inferred  that  a  content  of  7-18  per 
cent,  of  oxygen  entails  the  property  of  coking.  The  results  in 
the  table  on  the  opposite  page,  obtained  from  the  experiments 
of  W.  Stein  and  of  the  author,  however,  are  totally  against  such 
an  inference. 

"Of  the  Saxon  coals,  for  instance,  Nos.  7  and  8,  as  well  as 
Nos.  9  and  10,  while  having  a  very  similar  composition,  show 
entirely  different  results  by  the  coking  test.  The  same  is  true  of 
each  pair  of  the  Westphalian  coals  analyzed. 

"For  single  coal  fields,  it  is,  of  course,  possible  to  establish  some 
limits.  Richter,  for  instance,  has  done  this  for  the  coals  of  lower 
Silesia,  though  only  in  an  introductory  way: 

"(a)  So-called  coking  coals  contain,  with  few  exceptions, 
40  parts  of  disposable  hydrogen  per  1,000  of  carbon. 

"(6)  In  case  of  equal  content  of  disposable  hydrogen,  the 
coking  power  increases  the  more  the  combined  hydrogen  falls 
below  20  per  1,000  of  carbon.  Coals  of  20  per  1,000  content 
of  combined  hydrogen,  and  even  those  of  17  to  18  per  1,000  do 
not,  in  lower  Silesia,  belong  to  the  number  of  coking  coals, 
properly  speaking. 

"(c)  Although  the  above  may  be  accepted  as  the  rule,  it  must 
still  be  noted  that  sometimes  coals  of  almost  the  same  composition 
show  very  different  coking  properties. 

"A  sort  of  rule  may  be  deduced  as  follows,  from  the  analyses 
of  several  hundred  Westphalian  coals: 

"(a)  Coking  coals  (swelling  in  the  process  of  fusion)  contain, 
per  1,000  parts  of  carbon,  over  40  of  disposable  hydrogen  and  10 
of  combined  hydrogen,  or  under  40  of  disposable  hydrogen  and 
over  9  of  combined  hydrogen. 

"(6)  Open-burning  or  slagging  coals  (that  is,  fusing,  but  not 
swelling)  contain,  per  1,000  of  carbon,  over  34  of  disposable  hydro- 
gen and  over  9  of  combined. 

11  (c)  Close-burning  coals  contain,  per  1,000  of  carbon,  under 
40  of  disposable  hydrogen  and  under  9  of  combined. 

"The  property  of  fusing  or  not  fusing  finally  depends  on  the 
presence  or  absence  of  certain  carbon  compounds,  of  which  inti- 
mate knowledge  is  probably  not  attainable." 

Mr.  Richard  Thomas,  in  "A  Paper  on  Coke,"  read  before  the 
Alabama  Industrial  and  Scientific  Society,  submits  a  tabulated 
statement  showing  the  ultimate  composition  of  some  Welsh  coals, 
and  from  the  coking  or  non-coking  properties  of  these,  infers  that 
the  fusing  element  in  coals  consists  of  the  relations  of  the  hydro- 
gen to  the  carbon. 


TREATISE  ON  COKE 


33 


8* 


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8  3 


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M    C 


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two 


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t>  co 

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34  TREATISE  ON  COKE 

TABLE  SHOWING  COMPOSITION  OF  WELSH  COAL 


No. 

c 

Per  Cent. 

H 
Per  Cent. 

AT 

Per  Cent. 

0 

Per  Cent. 

5 
Per  Cent. 

Ash 
Per  Cent. 

1 

91.44 

3.46 

.21 

2.58 

.79 

1.52 

2 

84.87 

3.84 

.41 

7.19 

.45 

3.24 

3 

89.01 

4.49 

1.16 

1.65 

1.03 

2.66 

4 

89.78 

5.15 

2.16 

1.02 

.39 

1.50 

5 

81.72 

5  76 

.56 

8.76 

1.16 

2.04 

6 

87.48 

5.06 

.86 

2.53 

1.03 

3.04 

7 

82.75 

5  31 

1.04 

4.64 

.95 

5.31 

TABLE  SHOWING  AMOUNT  OF  COKE  AND  WHAT  WAS  VOLATILE 


No. 

Coke 
Per  Cent. 

H 
Per  Cent. 

JV 

Per  Cent. 

0 

Per  Cent. 

C 

Per  Cent. 

Hydrogen  to  Carbon 

1 

92  90 

3.46 

.21 

2.58 

.85 

{c2e.4}Anthracite 

2 

85.50 

3.84 

.41 

7.19 

3.06 

f  7-7  1         i 

{  C  22  1  }  Semianthracite 

3 

84.55 

4.49 

1.16 

1.65 

8.14 

(  J-f  1       i 
\C  19  8/  Bituminous 

4 

77.50 

5.15 

2.16 

1.02 

14.18 

{TT    I              ~. 
C  17  4  /Bituminous 

5 

68.40 

5.70 

.56 

8.76 

16.58 

r  J-f  1       i 
<  ^  +'„     >  Bituminous 

6 

72.94 

5.06 

.86 

2.53 

18.61 

{/•/  1       i 
C  1  7  1  I  Bituminous 

7 

67.10 

5.31 

1.04 

4.64 

21.91 

{^gjBitummous 

Mr.  Thomas  gives  the  following  descriptions  of  the  above  coals  : 
"Coal  No.  1,  or  Welsh  Anthracite. — This  coal  will  not  fuse, 
neither  will  the  lump  coke  like  the  other  coal.  The  analysis  shows 
92.9  per  cent,  of  coke  from  the  coal.  In  appearance,  it  is  more  like 
a  drying  up  coal  than  coke.  In  place  of  cells,  it  looks  more  like 
cracks.  By  disintegrating  the  coal,  and  using  about  6  per  cent,  of 
pitch,  the  latter  being  about  12  per  cent,  of  hydrogen  to  88  per 
cent,  of  carbon,  the  two  combined  make  a  very  strong  coke.  The 
fracture  did  not  show  the  cells  the  same  as  the  coking  coal,  but  was 
granulated  in  appearance.  They  claim  that  it  works  well  for 
foundry  purposes  and  commands  a  price  from  3  to  4  shillings  per 
ton  more  than  the  coke  made  in  the  same  locality  from  the  bitu- 
minous coal.  The  loss  in  volatile  matter  in  this  coal  is  very  small. 
The  difference  in  carbon  from  coal  to  coke  is  less  than  1  per  cent. ; 
the  analysis  shows  3.46  per  cent,  of  hydrogen,  and  2.58  per  cent,  of 
oxygen.  It  seems,  by  the  proportion  of  volatile  carbon  to  the 
amount  of  oxygen,  that  the  two  had  combined  into  carbonic  oxide. 
Had  the  carbon  and  the  hydrogen  combined,  it  would  have  formed 
the  light  carbide  of  hydrogen,  which  is  composed  by  weight  of 


TREATISE  ON  COKE  35 

75  per  cent,  of  carbon  to  25  per  cent,  of  hydrogen.  In  that  case, 
there  would  have  been  a  loss  of  over  10  per  cent,  of  carbon.  On 
the  other  hand,  if  the  amount  of  oxygen  had  combined  with  the 
hydrogen  and  formed  water,  the  amount  of  hydrogen  would  not 
have  exceeded  .32  of  1  per  cent.  It  is  very  clear  that  the  hydrogen, 
in  the  anthracite,  must  have  escaped  almost  in  a  pure  state  from 
the  coal,  and  mixed  with  the  oxygen  of  the  air  and  formed  water. 

"Coal  No.  2  has  a  little  more  hydrogen,  and  like  No.  1  it  will 
not  fuse,  neither  will  it  coke,  only  when  mixed  with  pitch,  or  some 
of  the  other  solid  volatile  carbons.  This  coal  would  have  to  be 
treated  the  same  as  No.  1  to  make  coke.  The  coking  of  No.  1 
was  discontinued  for  a  time,  owing  to  the  advance  in  the  price  of 
pitch,  there  being  such  a  demand  for  the  article  to  mix  with  the 
dry  non-fusible  coal,  to  make  patent  fuel. 

"Coal  No.  3. — This  coal  is  known,  the  world  over,  as  the  Aber- 
dare  and  Merthyr  smokeless  steam  coal.  This  is  2.33  less  in  carbon 
than  No.  1,  but  higher  in  hydrogen,  by  a  little  over  1  per  cent. 
It  has  only  1.65  per  cent,  of  oxygen,  and  it  shows  a  loss  of  carbon 
in  coking  of  8.14  per  cent.,  the  oxygen  being  so  low. 

"The  carbon,  in  this  instance,  must  have  formed  gas,  most  likely 
the  light  carbide  of  hydrogen.  This  coal  has  not  sufficient  hydrogen 
and  carbon  to  fuse,  but  the  lump  makes  a  good  furnace  coke  and 
is  used  very  extensively.  The  slack  of  No.  3  will  coke  when  dis- 
integrated with  richer  coal,  in  proportion  about  half  and  half,  or 
when  the  hydrogen  would  be  about  5  per  cent,  in  the  coal — or,  say, 
1  per  cent,  of  hydrogen  to  17.5  carbon.  The  two  combined  will 
yield  about  75  per  cent,  of  coke  from  the  coal. 

"Coal  No.  4  will  fuse  and  make  a  strong  coke,  and  is  a  coking 
bituminous  coal.  I  have  noticed  that,  whenever  it  gives,  say, 
75  per  cent,  of  coke  from  the  coal,  the  color  of  the  coke  is  dark 
gray  and  shows  the  cells  very  clearly;  but  it  will  not  have  a  smooth, 
silvery  gloss  on  it.  None  of  the  dry  coals  have. 

"Coal  No.  5. — This  coal  shows  8.06  per  cent,  less  carbon  than 
No.  4,  but  it  has  7.74  per  cent,  more  oxygen  in  it,  and  has  also 
.61  per  cent,  more  hydrogen.  The  hydrogen  is  1  to  16  of  carbon. 
This  will  make  a  bright  coke  of  silvery  appearance. 

"Coal  No.  6  makes  a  good  furnace  coke,  and  shows  the  cells  a 
little  darker  gray  in  color,  the  yield  being  rather  high  to  be  glossy. 

"Coal  No.  7. — This  coal  cokes  more  like  the  Connellsville,  of 
Pennsylvania,  than  any  I  have  ever  seen.  This  coke,  in  appear- 
ance, has  a  very  smooth,  silvery  gloss  when  cooled  in  the  ovens. 
The  best  coke  in  this  series  is  made  from  a  vein  called  the  Crepwr 
vein.  It  makes  a  good,  strong  furnace  coke,  and  is  largely  used 
for  foundry  purposes.  Owing  to  a  slate  roof,  some  of  which  falls 
in  mining,  the  slack  in  some  of  the  mines  is  washed,  but  the  vein 
is  free  from  all  impurities,  and  averages  about  8  feet  thick." 

He  concludes  that  No.  1  coal,  with  a  proportion  of  hydrogen  to 
carbon  of  1  to  26.4,  will  not  fuse  in  the  coke  oven.  No.  2  coal,  with 


36  TREATISE  ON  COKE 

a  proportion  of  1  to  22.1,  will  not  coke.  No.  3,  a  smokeless  steam 
coal,  inheriting  a  proportion  of  hydrogen  to  carbon  of  1  to  19.8, 
will  not  fuse  readily.  Nos.  4  to  7  embrace  the  fusing  or  coking 
coals.  The  best  relation  of  hydrogen  to  carbon  among  these  is 
found  in  No.  7,  which  is  reported  as  producing  a  coke  "more  like 
the  Connellsville."  This  coal  has  a  proportion  of  1  to  15.6;  hence, 
it  is  inferred  that  coals  inheriting  ratios  of  hydrogen  to  carbon,  as 
the  series  from  4  to  7  show,  are  good  coking  coals. 

It  may  be  of  interest  to  note  that  the  Connellsville  coking  coal 
inherits  relations  of  hydrogen  to  carbon,  in  its  composition,  of  1  to 
14  nearly.  The  Monongah  coal  of  West  Virginia  contains  the 
relations  of  hydrogen  to  carbon  of  1  to  10.7.  The  celebrated 
Durham  coking  coal  of  England  has  a  proportion  of  1  to  17.2.  All 
these  coals  fuse  in  a  very  thorough  manner,  making  excellent 
metallurgical  coke. 

On  the  other  side,  a  readily  fusing  coal  from  Ohio  has  its 
hydrogen  to  carbon  as  1  to  9.8,  which  indicates  a  close  relationship 
to  the  West  Virginia  variety. 

In  the  Saxony  and  Westphalia  coals,  two  samples  of  coal  afford 
proportions  of  1  to  17.4  and  1  to  17. 6  respectively;  the  former  made 
a  crumbling  coke,  while  the  latter  was  "caked  and  much  swollen." 

These  investigations  indicate  progress,  but  do  not  go  far  enough 
in  embracing  the  different  varieties  of  coals  with  their  varying  con- 
ditions to  enable  the  coke  manufacturer  to  determine  accurately, 
from  the  ultimate  analysis  of  his  coal,  whether  it  will  fuse  in  the 
oven  and  make  good  metallurgical  coke,  or  if  it  is  a  non-coking 
coal.  So  far  as  the  more  recent  investigations  indicate,  the  coking 
property  of  coal  depends  on  the  presence  of  certain  relations  of 
hydrogen  and  carbon,  with  the  interaction  of  these  from  certain 
conditions  not  yet  definitely  established. 

Prof.  W.  Carrick  Anderson,  of  the  University  of  Glasgow,  Scot- 
land, submits,  in  a  paper  read  before  the  Glasgow  Philosophical 
Society,  that,  in  every  case,  the  quantity  of  hydrogen  and  oxygen 
contained  in  the  coal  plays  a  more  important  part  than  the  carbon. 
Coals  very  rich  in  hydrogen  and  in  oxygen  no  longer  melt,  neither 
do  those  very  poor  in  hydrogen  and  oxygen.  He  gives  the  table 
on  the  following  page  exhibiting  the  series  of  solid  fuels,  arranged 
with  reference  to  their  chemical  composition  and  yield  of  coke. 

He  adds  that  it  is  evident  from  this  series  that  the  coking 
property  is  in  some  measure  bounded  by  the  following  limits: 
hydrogen,  5  to  6  per  cent. ;  oxygen,  10  per  cent. ;  free  hydrogen, 
4  per  cent.;  and  specific  gravity,  1.35.  Such  a  statement  cannot, 
however,  by  any  means  be  regarded  as  a  rule  of  general  applica- 
tion, especially  seeing  that  cases  of  isomerism  occur  among  coals 
in  which,  in  two  coals  identical  in  composition,  the  one  cokes  and 
the  other  does  not. 

Until  the  exact  relations  of  the  coking  elements  of  coal  are 
assuredly  determined,  it  will  be  the  safest  course,  in  ascertaining 


TREATISE  ON  COKE 


37 


the  coking  properties  of  the  coal,  to  have  a  sufficient  quantity  of 
it  tested  in  a  coke  oven.  This  will  settle  the  whole  matter  beyond 
any  doubt. 

SERIES  OF  FUELS 


Kind 

C 
Per 

Cent. 

H 
Per 

Cent. 

O 
Per 

Cent. 

Free 
H 
Per 

Cent. 

Coke 
Yield 
Per 
Cent. 

Specific 
Gravity 
Per  Cent 

Time  of  Formation 

Wood  

44 
60 
65 
75 
80 
85 
90 
95 

100 

6 
6 
7 
6 
6 
5 
4 
2 

50 
34 
28 
19 
14 
10 
6 
3 

2 

3 
4 
4 
4 
3 
H 

15 

20 
40 
50 
60 
70-80 
90 
95 

100 

.35 
.60 
1.00 
1.25 
1.30 
1.35 
1.40 
1.50 
(1.90) 
2.00 

>  Present  day 
Tertiary  and  chalk 

Carboniferous 
period 

Silurian 

Peat  
Brown  coal  
Coal  (a)  flaming..  . 
Coal  (6)  gas 

Coal  (c)  coking.  .  .  . 
Coal  (d)  lean  coal  . 
Coal  (e)  anthracite 
(and  coke) 

Graphite 

The  Connellsville  coal,  found  in  the  upper  coal  measures  and  at 
a  certain  distance  from  the  eastern  seaboard,  is  especially  adapted 
for  the  manufacture  of  coke.  It  holds  practically  32  per  cent,  of 
volatile  matter.  The  bed  is  8  to  10  feet  thick,  and  the  coal  has  a 
decided  columnar  structure.  In  mining,  the  coal  crumbles  into  a 
finely  divided  condition,  well  adapted,  without  further  preparation, 
for  charging  into  the  coke  ovens. 

The  central  West  Virginia  coals  are  much  more  bituminous  than 
the  Connellsville,  the  Monongah  coal  inheriting  38  per  cent,  of  vola- 
tile matter,  while  the  Pocahontas  coal,  in  the  southeastern  side  of 
the  state,  holds  only  20  per  cent,  of  volatile  matter.  These  are  the 
typical  coking  coals  of  these  sections  of  the  Appalachian  field. 

The  Kentucky,  Tennessee,  and  Alabama  coals  approach  in 
percentage  of  volatile  matters  the  Connellsville  coal,  and  make 
very  good  coke. 

In  the  central  and  western  fields  the  coals  are  quite  rich  in  bitu- 
minous matters,  and  as  yet  they  have  not  been  distinguished  in  the 
manufacture  of  coke.  With  our  present  inexperience  in  the  best 
methods  of  treating  these  coals,  in  preparing  them  for  coking,  and 
in  the  use  of  the  oven  best  adapted  for  securing  good  coke,  few 
attempts  have  been  made  in  these  respects.  It  is  evident  that 
experimental  work  along  these  lines  will,  in  the  near  future,  become 
a  necessity,  especially  in  eliminating  sulphur  from  these  coals. 

In  the  Rocky  Mountain  and  Pacific  coast  regions  no  sure  infer- 
ences can  be  drawn  from  the  chemical  composition  of  the  coal  as 
to  its  coking  properties.  In  one  locality  the  coal  cokes  readily, 
making  a  good  marketable  coke;  in  another,  a  coal  with  a  very 
similar  composition  will  not  coke,  but  if  placed  in  an  oven  it  will 
part  with  its  volatile  matter  without  fusing — the  result  will  be 


38  TREATISE  ON  COKE 

charred  coal.  The  only  sure  method  of  determining  the  value  of 
such  coals  for  the  manufacture  of  coke  is,  as  before  indicated,  to 
have  a  quantity  of  it  tested  in  a  coke  oven.  This  will  show  its  cok- 
ing or  non-coking  properties  without  any  doubt.  A  few  dollars 
expended  in  this  preliminary  work  will  save  a  great  many  in  the  end. 
The  kind  of  coke  oven  for  these  special  qualities  of  coal  can  be 
ascertained  by  consulting  some  reliable  expert  in  coke-oven  plants. 


IMPURITIES  IN  COAL 

The  impurities  in  coal  consist  of  ash,  sulphur,  and  phosphorus. 
The  ash  is  usually  a  negative  element,  having  little  chemical  influ- 
ence in  the  use  of  coal  and  coke,  unless  it  is  mainly  composed  of 
silicious  matter,  in  which  case  it  will  produce  "clinkers,"  which 
are  always  undesirable.  It  has  been  pointed  out  that  an  excess  of 
ash  in  the  coal  is  injurious  to  the  perfect  physical  development  of 
the  coke,  especially  in  its  hardness  of  body.  Economically  con- 
sidered in  coke  for  blast-furnace  use,  it  not  only  displaces  carbon, 
but  requires  increased  charges  of  limestone  and  coke  to  dispose  of 
it  in  the  slag.  Some  qualification  to  this  has  been  indicated  in 
the  smelting  of  the  dry  Lake  Superior  ores,  that  the  ash  in  coke 
contributes  somewhat  to  the  formation  of  slag  in  the  furnace — but 
ordinarily  it  is  an  expensive  application. 

The  sulphur  in  coal  is  usually  found  in  four  principal  chemical 
conditions;  viz.,  sulphide  of  iron,  FeS2  (iron  pyrites);  sulphate  of 
lime,  Ca5O4;  organic  sulphur,  i.  e.,  combined  with  carbon,  hydro- 
gen, and  oxygen;  and  free  sulphur,  i.  e.,  sulphur  not  in  combina- 
tion with  iron  or  other  elements. 

If  sulphur  is  present  in  the  coal  united  with  lime,  as  sulphide 
of  iron,  a  large  proportion  of  it  will  be  volatilized  in  coking;  but 
if  it  takes  the  form  of  sulphate  of  lime,  gypsum,  it  will  not  be 
volatilized  in  a  coke  oven.  The  organic  sulphur  remains,  for  the 
most  part,  in  the  coke. 

The  table  on  the  opposite  page  shows  the  percentage  of  sulphur 
volatilized  in  coking. 

This  table  is  from  volume  MM  of  the  Second  Geological  Sur- 
vey of  Pennsylvania,  by  Prof.  Andrew  S.  McCreath.  Professor 
McCreath  adds:  "Seven  coals  with  an  average  of  63.51  per  cent, 
of  their  sulphur  existing  as  free  sulphur  lost  34.57  per  cent,  of  the 
sulphur  by  coking;  on  the  other  hand,  eleven  coals,  with  an  average 
of  only  11.36  per  cent,  of  sulphur  not  combined  with  iron,  lost  37.88 
per  cent.  Again,  two  coals,  with  an  average  of  74.58  per  cent,  of 
the  sulphur  free,  lost  20.97  per  cent,  by  coking;  while  two  other 
coals,  with  only  2.20  per  cent,  of  the  sulphur  free,  lost  44.81  per 
cent.  In  the  presence  of  such  results,  therefore,  it  would  seem  to 
be  impossible  to  accept  the  statement  that  all  the  free  sulphur 
passes  off  with  the  volatile  matter  in  the  process  of  coking. 


TREATISE  ON  COKE 


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40  TREATISE  ON  COKE 

"In  the  25  coals  examined,  the  percentage  of  sulphur  expelled 
by  coking  varies  very  much,  the  maximum  amount  being  57.92 
per  cent.,  and  the  minimum  14.75  per  cent.  The  average  percent- 
age is  38.50;  and  the  average  percentage  of  free  sulphur  is  33.79. 

"Where,  therefore,  a  careful  handling  and  subsequent  washing 
of  the  coal  will  not  remove  the  excess  of  sulphur,  it  is  scarcely  to 
be  hoped  that  this  can  be  accomplished  by  the  usual  methods  in 
the  coke  ovens.  And  this  important  consideration  should  be  borne 
in  mind  when  selecting  coals  for  the  manufacture  of  coke  for  use 
in  blast  furnace  or  foundry." 

Effect  of  Acetic  Acid  in  Removing  Sulphur. — An  inquiry  from 
a  party  in  Kentucky,  as  to  the  value  of  acetic  acid  in  reducing  the 
volume  of  sulphur  in  coke,  was  submitted  to  Professor  McCreath, 
who  replied  as  follows: 

"A  sample  of  coal  containing  3J  per  cent,  of  sulphur  was  coked, 
and  a  spray  of  hot,  diluted  acetic  acid  was  thrown  on  the  incan- 
descent coke.  There  was  no  evidence  of  the  disengagement  of 
either  sulphureted  hydrogen,  sulphurous  acid,  or  sulphuric  acid. 
The  latter  would  seem  impossible. 

"The  test  was  duplicated,  using  a  stronger  solution  of  acetic 
acid.  The  result  was  equally  negative. 

"Two  separate  portions  of  the  same  coal  were  then  coked.  To 
the  one  nothing  was  added.  This  I  will  designate  as  'regular.' 
To  the  other,  a  spray  of  diluted  acetic  acid  was  added  to  the  incan- 
descent coke.  The  coking  process  was  continued  a  little,  when  a 
second  application  was  made,  completely  saturating  the  coke. 
Both  the  resultant  cokes  were  then  weighed,  and  the  'treated'  one 
yielded  1  per  cent,  less  coke,  due  of  course  to  increased  oxidation 
of  the  carbon.  Finally,  both  were  fused  and  a  determination  of 
the  sulphur  made,  the  results  obtained  being  as  follows: 

TREATED  WITH 
REGULAR     ACETIC  ACID 
Sulphur,  per  cent,  in  coke 2.987  2.755 

"The  difference  is  so  slight  that  the  results  for  all  practical 
purposes  may  be  considered  the  same,  and  they  demonstrate  that 
no  desulphurization  of  the  coke  takes  place  under  the  treatment 
submitted." 

Phosphorus  in  the  coal  usually  goes  over  to  the  coke;  it  is  not 
eliminated  in  the  coke  oven. 

The  investigation  of  the  volume  of  phosphorus  contained  in  coals 
suitable  for  the  manufacture  of  coke  for  steel-making  purposes, 
discloses  the  fact  that  this  volume  of  phosphorus  varies  from  a 
mere  trace  to  a  maximum  of  .1248  per  cent.  In  the  examination 
of  24  coals  from  the  large  Pittsburg  bed,  the  average  was  found 
to  be  .0217  per  cent.,  which  would  give  to  the  coke  an  average  of 
.0344  per  cent.  The  great  necessity  of  the  utmost  care  in  selecting 


TREATISE  ON  COKE 


41 


coals  for  the  manufacture  of  coke  for  metallurgical  uses  as  free 
from  the  impurities  of  ash,  sulphur,  and  phosphorus  as  possible, 
will  readily  appear.  The  following  table  of  Pennsylvania  coals 
affords  some  typical  examples: 


PERCENTAGE  OF  PHOSPHOJRUS  IN  PENNSYLVANIA  COAL  AND  COKE 


Name  of  Coal 

County 

Coal  Bed 

Phos- 
phorus in 
Coal 
Per  Cent. 

Phos- 
phorus in 
Coke 
Per  Cent. 

Henderson  's 

Washington 

Washington 

1667 

2818 

Redds' 

Washington 

Pittsburg 

0943 

1551 

Penn  Gas  Coal  Co  
Millwood 

Westm'land 
Westm  'land 

Pittsburg 
Pittsburg 

trace 
0801 

trace 
1177 

Connellsville 

Fayette 

Pittsburg 

.0111 

0161 

Cambria  Iron  Co        ... 

Cambria 

B 

trace 

trace 

LOCALITIES  OF  PHOSPHORUS  IN  THE  CONNELLSVILLE  SEAM 


PER  CENT.  OF  PHOSPHORUS 


Roof 
to 
Bottom 

Bottom* 

Middlet 

Topf 

Above  5-Foot  Binder 

Upper 
12  Inches 

Middle 

Lower 
12  Inches 

.009 

.010 

.023 

.054 

.031 

.038 

.019 

.001 

.010 

.027 

.033 

.029 

.017 

.022 

.001' 

.007 

.034 

.043 

.035 

.053 

.012 

.001 

.004 

.009 

.017 

.008 

.007 

.018 

.015 

.015 

.087 

.019 

.007 

.016 

.005 

.025 

.002 

.030 

.174 

.109 

.060 

.068 

.015 

.047 

.016 

.028 

.018 

1 

.015 

.017 

.002 

.008 

.019 

.017 

| 

.026 

.021 

.003 

.044 

.082 

.090 

.011 

.010 

.021 

.006 

.009 

.029 

.062 

.038 

.013 

.020 

.011 

.034 

.032 

.025 

.004 

.043 

.035 

.021 

.005 

.006 

.069 

.062 

.025 

.003 

.018 

.035 

.035 

,  .006 

.079 

.013 

.003 

.114 

.022 

.014 

.105 

.019 

.013 

Average 

.0143 

.0094 

.0186 

.0393 

.062 

.0362 

.0277 

*  Bottom  means  3-foot  binder  down, 
t  Middle  means  between  3-  and  5-foot  binder. 
t  Top  means  above  5-foot  binder. 

§  The  upper  and  lower  sample  left  only  about  2  inches  of  coal  between  the  two;  conse- 
quently, no  sample  from  the  middle  was  taken. 


42  TREATISE  ON  COKE 

Phosphorus  in  Connellsville  Coal. — During  the  year  1896,  Mr. 
O.  W.  Kennedy,  late  General  Superintendent  of  the  H.  C.  Frick 
Coke  Company,  had  a  series  of  tests  made  to  determine  the  local- 
ities of  the  phosphorus  in  the  Connellsville  coal  seam.  The  pre- 
ceding table,  in  detail,  will  afford  the  results  of  these  tests.  It  was 
submitted,  in  explanation,  that  "this  sampling  was  made  at  mines 
showing  phosphorus  higher  than  the  average  of  the  region." 

It  is  manifest  from  this  table  that  the  upper  section  of  this 
large  coal  bed  contains  the  greatest  amount  of  phosphorus.  It 
is  also  evident  that  the  percentage  of  this  undesirable  element 
increases  gradually  from  bottom  to  top  of  the  coal  bed. 

Effect  of  Impurities  in  Coke  on  Pig  Iron. — The  sulphur,  when 
present  in  coke  in  large  volume,  confers  on  pig  metal  the  undesir- 
able property  of  "red-shortness."  Coke  for  use  in  blast-furnace 
work  producing  Bessemer  pig  should  not  contain  over  1  per  cent, 
of  sulphur  as  a  maximum  volume.  Coke  containing  .50  per  cent, 
to  .75  per  cent,  of  this  element  would  be  much,  more  desirable  in 
the  manufacture  of  pig  iron  for  making  steel.  An  undue  volume 
of  phosphorus  produces  an  opposite  quality  in  the  metal  made  by 
it — the  condition  of  "cold-shortness" — that  is,  metals  made  by 
coke  containing  an  excess  of  these  dangerous  elements  are  found 
to  be  brittle  in  their  hot  and  cold  conditions.  As  little  or  none  of 
the  phosphorus  in  the  coal  is  eliminated  in  the  process  of  coking, 
it  is  of  the  utmost  importance  to  select  coals  for  the  manufacture 
of  coke  for  Bessemer  uses  as  low  as  possible  in  this  dangerous 
impurity.  The  table  on  page  41  shows  .0111  per  cent,  of  phos- 
phorus in  the  Connellsville  coal. 

Portions  of  the  ash  and  sulphur  can  be  removed  from  the  coal 
for  coke  making  by  the  processes  of  crushing  and  washing  (see 
Chapter  III),  but  the  phosphorus  usually  goes  over  in  full  to  the 
coke  and  finally  to  the  pig  metal  in  blast-furnace  work. 


CHAPTER  HI 


PREPARATION  OF  COALS  FOR  THE  MANUFACTURE 

OF  COKE 

Necessity  for  Preliminary  Preparation  of  Coke. — It  is  now  quite 
manifest  that  we  have  reached  a  period,  in  the  United  States  of 
America,  in  which  steel  is  rapidly  displacing  iron  in  the  arts  and 
manufactures,  especially  for  structural  uses.  This  expansion  of 
the  use  and  manufacture  of  steel  carries  with  it  the  necessity  for 
a  pure  coke  fuel,  and  it  becomes,  therefore,  the  duty  as  well  as 
the  interest  of  the  coke  manufacturer  to  adopt  such  methods  in 
the  preparation  of  coal  for  making  coke  as  will  insure  the  purest 
and  best  possible  product. 

Although  there  is  a  very  great  source  of  supply  of  coal  for  the 
manufacture  of  coke,  covering  an  area  in  the  United  States  of 
North  America  of  about  344,440  square  miles,  it  is  evident  that 
only  a  small  portion  of  these  coal  fields  affords  the  best  coal  for 
coke  making — such  as  the  Connellsville,  Punxsutawney,  Alleghany, 
and  Broad  Top  in  Pennsylvania;  Pocahontas  in  Virginia;  and  the 
new  regions  of  coking  coals  in  West  Virginia.  Alabama  also  affords 
a  very  good  coal  for  coke  making.  In  Kentucky,  at  Pineville, 
and  Big  Stone  Gap,  excellent  coking  coals  are  found  in  abundance. 
At  El  Moro,  in  Colorado,  very  good  coke  is  made  from  a  large 
bed  of  coking  coal.  But  with  all  these  and  many  others  yet  to 
be  developed,  the  aggregate  ratio  of  the  best  coking  coals  to  the 
whole  coal  area  is  very  small. 

As  long  as  the  supply  of  coke  can  be  maintained  from  these  good 
coking  coals,  the  methods  of  coking  do  not  urge  or  compel  extended 
consideration ;  but  when  the  less  valuable  coals  for  coking  purposes 
come  into  use,  the  studies  of  the  preparation  of  the  coal  for  coking 
with  the  kind  of  coke  oven  best  adapted  for  each  quality  of  coal 
will  become  of  vital  importance.  When  the  time  approaches  for 
these  investigations  to  be  taken  up  by  coke  makers,  it  will  be  found 
that  three  principal  conditions  will  require  careful  study:  (1)  the 
preparation  of  coal  for  coking;  (2)  the  kind  of  coke  oven  best 
adapted  for  securing  the  best  quality  of  coke  from  each  variety  of 
coal;  (3)  the  saving  of  the  by-products  in  coking,  consisting  of 
sulphate  of  ammonia  and  tar.  This  will  also  require  arrangements 
in  coke  ovens,  as  well  as  the  outside  conduits,  condensers,  etc. 

43 


44  TREATISE  ON  COKE 

The  rather  poor  quality  of  coking  coals  on  the  continent  of 
Europe  has  long  ago  compelled  thorough  attention  to  the  prepara- 
tion of  these  coals  for  coking,  as  well  as  to  the  development  of  the 
oven  best  suited  to  their  wants  in  making  from  them  the  best 
possible  coke,  and,  during  the  past  decade,  to  the  saving  of  the 
by-products  in  coking.  The  American  coke  manufacturer  has 
before  him  a  much  easier  task  than  the  Belgium,  German,  or  French 
coke  makers,  the  larger  supply  of  coking  coal  requiring  no  special 
treatment  in  producing  the  best  qualities  of  coke.  Even  when  the 
exhaustion  of  these  good  coals  approaches,  the  second  quality  will  be 
found  to  be  superior  to  the  continental  coals.  From  the  large  and 
increasing  use  of  coke,  it  is  evident  that  its  manufacture  will  demand 
the  earnest  and  diligent  efforts  of  those  in  charge  of  the  several  proc- 
esses in  its  preparation  and  coking.  Nor  is  this  industry  any  excep- 
tion to  the  general  law  governing  all  industries:  small  beginnings, 
protracted  and  anxious  struggles  for  success,  with  the  reward  crown- 
ing all  persistent  and  well-directed  efforts.  There  is,  therefore,  a 
deep  interest  attached  to  the  study  of  the  several  steps  in  the  upward 
progress  in  the  manufacture  of  coke,  especially  in  its  early  stages 
and  up  to  its  present  advanced  progress  in  the  industrial  arts. 

Large  areas  of  the  best  coking  coals  require  no  special  treat- 
ment, but  the  coals  are  charged  into  the  coke  ovens  as  they  come 
out  of  the  mines.  In  the  Connellsville  region,  with  a  few  excep- 
tions, no  preparatory  work  on  the  coal  is  attempted,  and  it  is 
charged  into  the  ovens  as  it  comes  from  the  mines.  On  account  of 
the  softness  of  the  coal  and  its  attenuated  columnar  structure,  this 
coal  is  usually  broken  into  small  pieces,  in  mining,  and  this  break- 
age, with  that  due  to  the  handling  into  tipple  bins  and  larries, 
gives  pieces  sufficiently  small  to  assure  good  results  in  coking. 
A  second  type  of  this  coal  is  found  in  the  Flat  Top  region  of  Vir- 
ginia. The  coal  is  mined  in  more  solid  lumps  than  the  Connells- 
ville, but  it  is  broken  up,  and  the  screenings  are  used  in  making 
coke.  The  bituminous  coals  of  the  Central  and  New  River  sections 
of  West  Virginia  are  usually  broken  and  the  screenings  washed 
preparatory  to  coking. 

The  manufacture  of  coke  from  coal  screenings,  in  the  Kanawha 
Valley,  produces  a  very  good  quality  of  coke,  but  by  using  the 
whole  body  of  the  coal  bed,  excluding  a  thin  top  bench  of  splint 
coal,  a  coke  is  made  nearly,  if  not  quite,  equal  to  the  best  standard 
Connellsville.  The  Alleghany  Mountain  coals  are  frequently  charged 
into  the  ovens  as  they  come  out  of  the  mine,  but  the  best  results  are 
assured  by  breaking  the  coal  or  by  breaking  and  washing.  From  the 
experience  gained  in  the  use  of  these  typical  coking  coals,  the  meth- 
ods of  treatment  of  representatives  of  these  types  will  be  apparent. 

The  annual  product  of  coke  required  in  blast-furnace  and  other 
metallurgical  operations  during  the  year  1902  was  25,401,730  net 
tons.  As  it  requires  an  average  of  1 .6  net  tons  of  coal  to  make  1  net 
ton  of  coke,  the  draft  on  the  coking  coal  mines  for  the  above  year 


TREATISE  ON  COKE  45 

was  39,604,007  net  tons  of  coal.  The  area  of  coking  coals  to  the 
total  coal  area  of  the  United  States  has  not  been  accurately  deter- 
mined, but  it  is  evidently  small.  As  only  a  very  limited  proportion 
of  this  coking  coal  area  can  be  used  for  coking,  without  preparation 
by  crushing,  classifying,  and  washing,  it  is  evident  that,  with  the 
present  great  demand  for  coke,  this  small  section  of  pure  coking 
coal  will  be  exhausted  within  a  not  very  extended  time.  At  this 
time,  coke  manufacturers  have  invaded  the  areas  of  the  second- 
class  coking  coals  which  require  preparatory  cleansing,  and  it  is 
evident  that  the  preparation  of  these  coals  for  the  manufacture  of 
good  metallurgical  coke  is  now  most  important. 

In  the  presence  of  so  many  varieties  of  coal-crushing  and  wash- 
ing machines,  evidently  designed  to  meet  the  several  wants  in  the 
treatment  of  the  different  qualities  of  coals,  there  can  be  no  reason- 
able excuse  for  using  slaty  coals  in  the  manufacture  of  coke.  This 
essential  requirement  of  clean  coke  in  metallurgical  operations  is 
still  more  imperative  when  it  is  considered  that  the  slates  of  the 
coal  go  over  into  the  coke  and  carry  with  them  the  associated 
sulphur.  In  furnace  operations,  especially  when  slate  in  the  coke 
is  silicious,  an  increased  charge  of  limestone  will  be  required  to 
eliminate  these  impurities,  and  this  will  make  it  further  necessary 
to  add  to  the  fuel  charge  also.  Besides  all  this,  there  is  the  danger 
of  the  presence  of  sulphur  in  the  pig  metal  produced,  if  it  is  designed 
for  the  manufacture  of  steel.  It  is  therefore  evident  that  the  only 
safe  plan  in  the  manufacture  of  coke  for  metallurgical  uses  is  to  use 
only  a  pure  quality  of  coal ;  but  in  case  this  cannot  be  secured  and 
a  second  quality  must  be  used,  its  cleansing,  by  crushing  and 
washing,  becomes  an  absolute  necessity. 

In  America,  with  its  ample  areas  of  the  best  qualities  of  coals, 
it  is  only  necessary  at  this  time  to  require  clean  mining  to  produce 
coal  of  great  purity  for  manufactures  and  in  the  production  of 
coke.  At  many  of  the  coal  mines  in  Europe,  coal  washing  of 
fuel  for  manufacturing  purposes  is  coming  into  very  general  favor; 
but  in  America,  with  its  superior  qualities  of  coals,  it  is  only  neces- 
sary to  cleanse  the  secondary  or  slaty  coals  in  preparation  for  the 
manufacture  of  coke. 

The  impurities  in  these  coals  consist  of  shales,  iron  pyrites, 
ferrous  sulphide  (FeS?),  sulphate  of  lime,  argillaceous  matter,  and 
phosphorus.  The  principal  element  is  sulphur,  with  its  organic 
condition  and  combinations. 

Sulphur  is  found  in  five  principal  physical  conditions: 

1.  Pyrites  is  usually  found  in  lenticular  pieces  as  well  as  in 
balls;  occasionally  it  forms  the  filling  of  the  stems  of  the  larger 
plants  of  the  coal  flora.     In  all  these  conditions  it  can  be  separated 
from  the  coal  by  a  process  of  crushing  or  by  crushing  and  washing. 

2.  Where  the  sulphur  is  found  in  -the  strata  thinly  inter- 
leaved in  the  coal,  the  process  of  separation  becomes  more  difficult, 


46  TREATISE  ON  COKE 

requiring  the  coal  to  be  broken  into  very  small  sizes,  with  careful 
classification  of  the  different  sizes,  in  preparation  for  the  ultimate 
operation  in  the  washer. 

3.  Occasionally,  the  sulphur  is  found  in  the  coal  in  little  disks, 
like  fish  scales ;  these  present  a  still  more  difficult  condition  in  the 
process  of  removing  the  sulphur,  as  the  sulphur  disks  are  light  and 
in  the  fine  pulverized  condition  of  the  coal  many  of  them  are  carried 
over  the  edge  of  the  washer  pan  with  the  coal.     The  water  used  in 
washing  should  not  be  reused,  as  it  would  carry  back  some  of  these 
sulphur  disks,  increasing  the  undesirable  element. 

4.  In   the   combination    of   sulphur   with   lime,    as   sulphate, 
gypsum,  usually  found  in  thin  plates  in  the  coal,  some  of  it  can  be 
removed  in  the  process  of  breaking  and  washing,  but  all  that  goes 
over  to  the  coke  is  in  a  fixed  or  negative  condition  as  to  its  action 
when  used  in  blast-furnace  operations. 

5.  When  sulphur  is  found  in  organic  combination  with  the 
coal,  supposed  to  be  combined  with  carbon  and  hydrogen,  very 
little  of  it  can  be  removed;  it  goes  over  mainly  to  the  coke. 


CRUSHING  COAL 

Advisability  of  Crushing  Coal  Before  Coking. — In  practice,  it  has 
been  discovered  that  breaking  the  coal  that  comes  from  the  mine  in 
large  lumps,  especially  when  the  percentage  of  its  volatile  matter  is 
small,  adds  to  the  value  of  its  coke.  The  importance  of  this  dis- 
integration of  the  coal  before  it  is  charged  into  the  oven  will  readily 
appear  when  it  is  understood  that  in  this  condition,  other  things 
being  equal,  the  fusing  elements  assumed  to  be  in  the  volatile 
matter  are  utilized  to  the  utmost.  It  has  been  found  that  a  mixture 
of  lumps  and  fine  or  small  coal  fuses  unevenly  in  the  process  of 
coking  in  the  oven;  the  fine  coal  fusing  rapidly,  while  the  lumps 
require  more  time  for  the  coking  process  to  reach  the  middle  of  the 
lumps.  It  follows,  therefore,  that  all  coals  will  be  benefited  for 
making  a  uniform  quality  of  coke  and  securing  the  full  time  in  the 
oven,  by  being  disintegrated  before  being  charged  into  the  coke 
oven,  even  if  they  do  not  require  the  further  process  of  washing. 

In  the  selection  of  machinery  for  disintegrating  or  washing  coal, 
or  both,  it  will  be  wise  to  consult  those  experts  in  these  processes 
who  have  made  these  practical  operations  special  studies.  A  gen- 
eral principle  should  govern  in  these  matters,  to  insist  on  the  appli- 
cation of  the  simplest  machinery  with  the  largest  practicable 
automatic  service. 

Every  variety  of  coal  will  require  special  apparatus  for  its  treat- 
ment, and  the  proper  apparatus  can  be  determined  only  by  a  careful 
study  of  the  physical  and  chemical  properties  of  the  coal.  All  coal 
requiring  washing  should  be  carefully  classified.  This  will  insure 
the  most  efficient  removal  of  slate  or  other  impurities,  as  it  will 


TREATISE  ON  COKE 


47 


afford  the  best  condition  for  their  separation  in  the  washer  by  the 
difference  in  their  specific  gravities ;  the  coal  of  equal  size  being  the 
lighter  will  rise,  while  the  heavier  matter,  slates  or  pyrites,  will  sink 
in  the  pulsing  water  of  the  washers.  Some  coals  have  their  slaty 
impurities  so  mixed  with  fireclay  that  they  melt  in  the  water  in 
the  washer.  Efforts  have  been  made  to  treat  these  difficult  coals 
in  the  dry  way,  by  passing  the  classified  products  through  a  current 
of  air,  the  separation  being  effected,  just  as  in  water,  by  the  differ- 
ence in  the  specific  gravities  of  the  coal  and  its  impurities.  Other 
methods  have  been  tried  with  indifferent  success.  If  an  examina- 
tion of  the  character  of  a 
coal  shows  that  it  requires 
special  and  expensive 
appliances,  with  doubtful 
results,  it  will  be  well  for 
the  coke  manufacturer  to 
avoid  attempting  to  use  it. 

Bradford  Coal  Breaker. 

For  the  disintegration  of 
coals  requiring  this  pre- 
paratory process,  with  the 
removal  of  slate  and  py- 
rites, the  Bradford  coal 
breaker,  shown  in  section 
and  plan  in  Fig.  1  (a)  and 
(b) ,  will  be  found  well 
adapted  and  economical. 
It  is  simply  a  drum  or  cylin- 
der of  iron  parts,  having  its 
lagging  perforated  to  gauge 
the  size  to  which  it  is 
desired  to  reduce  the  coal. 
This  is  accomplished  by 
the  percussioa  of  the  coal 
falling  in  the  interior  of  the 
revolving  drum  from  the 
upper  to  the  lower  sections. 
The  length  of  this  fall,  or 
the  diameter  of  the  drum, 
is  made  to  meet  the 

requirements  of  the  coal.  If  the  coal  is  soft  and  friable,  the  diam- 
eter is  minimum;  if  the  coal  is  hard  and  tenacious,  the  diameter 
of  the  drum  is  increased  accordingly. 

The  drum  is  fed  with  coal  at  one  end  and  the  slate  and  other 
refuse  is  discharged  at  the  other  end ;  the  pure  coal  passes  through 
the  meshes  in  the  lagging  of  the  drum  and  is  received  into  a  pit 
from  which  it  can  be  elevated  to  any  desired  level. 


(b)  Plan  With  Bin  Removed 
FIG.  1.     BRADFORD  PATENT  COAL  BREAKER 


48  TREATISE  ON  COKE 

It  is  worthy  of  note  that  this  method  of  disintegration,  with 
separation  of  slates  and  pyrites,  also  removes  bony  coal,  as  the 
force  of  the  fall  in  the  drum  is  regulated  to  afford  just  sufficient 
concussion  to  break  the  purer  portions  of  the  coal,  leaving  the 
bony  coal  unbroken  and  discharging  it  with  the  other  impurities. 

The  Bradford  patent  coal  breaker  as  put  on  the  market  at 
present  by  Messrs.  Heyl  &  Patterson,  of  Pittsburg,  Pennsylvania, 
who  control  and  build  it,  differs  very  materially  from  its  original 
form,  which  consisted  of  a  cylinder  supported  on  stationary  rollers. 
In  this  shape,  it  was  not  found  very  satisfactory,  but  was  operated 
long  enough  to  demonstrate  the  value  of  the  principles  involved. 
The  breaker,  as  now  constructed,  has  trunnions  cast  on  both  heads, 
which  carry  the  entire  weight.  The  bearings  are  protected  from 
the  dust  and  are  provided  with  thorough  lubricating  devices,  thus 
reducing  the  amount  of  power  consumed  to  a  minimum. 

The  elevation  of  the  breaker  shows  the  method  of  supporting 
it;  also,  the  driving  mechanism.  The  diameter  of  the  breaker  a 
varies  from  7  feet  to  12  feet,  depending  on  the  hardness  of  the 
coal — 9  feet  diameter  being  the  general  size  used;  the  length 
varies  with  the  results  to  be  obtained.  The  heads,  with  trunnions 
and  spreaders,  are  made  of  cast  iron  of  proper  proportions.  The 
lagging,  or  mesh,  which  consists  of  steel  plates  perforated  with 
holes  varying  from  J  inch  to  2^  inches  square,  is  securely  fastened 
to  the  separators.  To  the  plates  are  bolted  cast-iron  fingers  that 
aid  in  breaking  the  coal  as  it  falls  on  them.  To  one  of  the  heads 
is  fastened  a  segment  gear  that  engages  in  a  pinion  on  the  counter- 
shaft placed  on  top  of  the  bents  supporting  the  breaker. 

The  coal  passing  into  one  end  of  the  breaker  under  the  trunnion, 
is  picked  up  by  longitudinal  shelves  and  discharged,  falling  on  per- 
forated plates;  that  which  is  of  proper  size  then  passes  through  the 
mesh  and  the  larger  pieces  are  picked  up  by  the  next  shelf  and  again 
thrown  down.  The  coal,  in  falling  from  the  shelf,  has  not  only  the 
force  derived  from  its  own  gravity,  but  receives  a  very  considerable 
additional  force  from  the  momentum  of  the  breaker.  The  fingers 
not  only  aid  in  the  breaking  of  the  coal  when  it  falls  on  them,  but, 
being  so  designed  as  to  form  portions  of  spirals,  can  be  regulated 
either  to  rapidly  advance  the  body  of  the  coal  and  impurities  to 
the  opposite  end  of  the  breaker,  or  to  retard  its  progress.  Fastened 
in  the  opposite  head  of  the  breaker  from  that  at  which  the  coal 
enters  are  wings,  which  discharge  the  substance  that  reaches  them. 

The  principle  involved  in  the  separation  in  this  machine  is  that 
the  slate  and  sulphur  are  usually  harder  than  the  coal  and  a  fall 
sufficient  to  break  the  coal  will  not  break  them.  The  bony  coal 
is  usually  harder  and  always  very  much  tougher,  and  will  not 
break  with  the  same  fall  or  force  as  the  coal.  By  varying  the 
speed  of  the  breaker,  the  force  of  the  fall  can  be  increased  or 
decreased;  and  with  the  adjustment  of  the  fingers,  the  impurities 
can  be  retained  in  the  breaker  until  all  the  coal  is  freed  from  them. 


TREATISE  ON  COKE  49 

Pieces  of  iron,  such  as  miners'  wedges,  couplings,  etc.,  which 
frequently  get  among  the  coal  and  cause  breakage  in  most  machines 
for  this  work,  will  pass  through  the  breaker  and  be  discharged  by 
the  wings  at  the  end  without  any  damage  to  the  machinery.  The 
speed  of  the  breakers  never  exceeds  20  revolutions  per  minute 
and  they  require  but  7  horsepower  when  operated  to  full  capacity. 
The  capacity  of  the  breaker  varies  from  300  to  700  tons  per  day, 
according  to  the  mesh,  hardness  of  coal,  and  amount  of  impurities 
to  be  removed. 

As  it  is  necessary  to  have  a  regular  supply  of  coal  for  the 
breakers  to  secure  the  best  results,  a  cylinder  feeder  is  used  in  con- 
nection with  the  breaker.  This  feeder  b  is  placed  under  the  bin  c 
and  at  the  end  of  the  breaker  a.  It  has  two  pockets,  which,  as  it 
rotates,  are  filled  and  discharged  into  the  chute  that  leads  to  the 
breaker.  It  will  handle  successfully  the  largest  lump  or  run-of- 
mine  coal,  allowing  the  bin  above  it  to  be  completely  filled.  The 
feeder  is  not  only  valuable  for  regulating  the  supply  of  coal  to  the 
breaker,  but  in  plants  where  the  coal  is  handled  after  leaving 
the  breaker,  it  prevents  the  overloading  of  the  elevators  or  con- 
veyers. The  coal  is  dumped  from  the  tipple  d  into  the  bin  c\ 
from  there  it  is  fed  into  the  breaker  a  by  the  feeder  b;  from  the 
breaker,  it  passes  into  the  bin  e,  and  is  then  loaded  into  the  larry  /. 
The  breaker  is  run  by  the  engine  g. 

The  cost  of  a  plant  of  one  9-foot  breaker,  such  as  is  illustrated 
in  Fig.  1,  and  installing  the  same  ready  for  operation,  exclusive  of 
boiler,  does  not  exceed  $3,000.  A  plant  of  this  size  requires  very 
little  attention  and  it  is  unusual  for  additional  help  to  be  employed 
other  than  that  required  for  handling  the  coal  on  the  tipple. 

There  are  now  eight  plants  comprising  twelve  breakers  in 
Western  Pennsylvania  and  three  plants  in  other  states.  The  largest 
plant  is  that  of  the  Rochester  and  Pittsburg  Coal  and  Iron  Company 
at  Walston,  Pennsylvania,  which  has  three  breakers  with  a  daily 
capacity  of  1,200  tons  through  a  5-inch  mesh,  and  elevators  for 
lifting  coal  to  a  vertical  height  of  80  feet  and  discharging  it  into 
a  storage  bin,  as  well  as  a  conveyer  for  removing  refuse;  the  expense 
for  labor  operating  this  plant  does  not  exceed  $2.50  per  day. 

The  Vesta  Coal  Company,  at  Lucyville,  Pennsylvania,  is  opera- 
ting one  12-foot  breaker,  with  IJ-inch  mesh,  that  has  a  daily 
capacity  of  750  tons.  This  plant,  being  situated  in  the  fourth 
pool,  Monongahela  river,  handles  probably  as  hard  a  coal  as  is 
coked  any  place  in  the  country.  It  does  not  employ  any  help 
except  that  necessary  for  the  dumping  of  coal  on  tipple. 

At  the  large  works  of  the  Cambria  Steel  Company,  Johnstown, 
Pennsylvania,  this  breaker,  as  shown  in  Fig.  1,  is  capable  of  break- 
ing 60  tons  per  hour.  During  a  continuous  run  of  17  days  at  this 
plant,  with  the  use  of  3,556.7  net  tons  of  coal  as  it  came  out  of  the 
Rolling  Mill  Mine,  35.5  net  tons  of  slates  and  pyrites  were  removed 
in  passing  through  the  breaker,  which  shows  a  reduction  of  these 


50 


TREATISE  ON  COKE 


impurities  of  nearly  1  per  cent.  Estimating  the  cost  of  engineer, 
oil,  steam,  etc.,  at  $40  for  these  17  days  of  trial,  the  expense  of 
this  work  of  breaking  the  coal  is  about  1^  cents  per  net  ton. 

The  following  is  an  estimate  of  the  cost  of  this  plant  complete 
and  ready  for  operating: 

Chute  and  screens  in  place $     228 . 00 

Bradford   breaker,    with   feeder,    hopper,    elevator, 

conveyers,  belts,  shafting,  and  pulleys,  in  place  .  4,722.00 

Engine  pipes  and  fittings 1,126. 60 

Siphon  and  strainer 17.25 

Foundations,  bolts,  etc 1 ,729.  51 

Lumber. 1,095.89 

Labor,  masons,  carpenters,  etc. .  .• 2,882.  91 


Total $11,802.16 

This  machine  is  well  adapted  for  treating  coals  in  which  the 
sulphur  occurs  in  lenticular  pieces  or  balls  of  pyrites.  It  removes 
pyrites,  slate,  and  other  large  impurities,  but  its  value  terminates 
with  this  quality  of  coal.  It  has  its  main  value  in  removing  these 
impurities  from  steam  coals  when  they  are  designed  for  use  for 
firing  boilers,  especially  in  the  preparation  of  coal  to  be  used  in 
mechanical  stokers,  as  it  can  be  made  to  reduce  the  coal  to  sizes 
suitable  for  these  purposes. 


STEDMAX'S  COAL  BREAKER 


Stedman's  Coal  Breaker  and  Disintegrator. — The  Stedman 
Foundry  and  Machine  Works,  of  Aurora,  Illinois,  presents  two 
machines  for  the  treatment  of  coal  in  preparing  it  for  coking:  a 
coal-breaking  and  a  coal-disintegrating  appliance. 

The  Stedman  coal  breaker,  Fig.  2,  is  designed  to  break  the 
coal  to  the  size  of  walnuts  or  marbles,  to  be  followed  by  the  usual 


TREATISE  ON  COKE 


51 


processes  of  classification  and  washing  to  remove  the  slate  and 
sulphur  before  charging  the  coal  into  the  coke  oven.  It  is  appli- 
cable to  all  coals  requiring  cleansing  by  crushing  and  washing. 

The  Stedman  disintegrator,  Fig.  3,  is  a  strongly  made  machine 
to  pulverize  coal  to  a  uniform  fineness  of  cracked  wheat  or  corn 
meal.  It  is  designed  for  use  in  treating  the  purer  coals  that  do 
not  require  to  be  washed.  This  crushing  of  coal  for  coking  is 
helpful  in  utilizing  the  volatile  matters,  especially  in  coals  inherit- 


FIG.  3.     STEDMAN'S  DISINTEGRATOR 

ing  small  volumes  of  fusing  matters,  as  it  enables  the  heat  of 
the  oven  to  be  diffused  simultaneously  through  the  charge  of 
coal,  quickly  fixing  and  securing  the  utmost  possible  fusion  of 
the  coal  in  the  process  of  coking.  The  matter  of  determining 
the  size  to  which  the  coal  should  be  broken  by  either  of  these 
machines  can  be  determined  by  the  quality  and  the  chemical 
composition  of  the  coal.  The  same  consideration  will  apply  to 
the  preparation  of  similar  coals  requiring  the  additional  treatment 
of  washing.  These  matters  are  mainly  local  and  practical,  and 
the  manufacturer  of  coke  will  be  called  on  to  exercise  judgment 
in  this  preparatory  treatment  of  coal  from  his  previous  experi- 
ence. The  evidence  of  this  work  will  be  determined  by  the  work 
of  the  coke  oven. 

The  following  statements  exhibit  the  estimated  cost  and  work 
of  these  machines: 


52  TREATISE  ON  COKE 

ELEVATOR,  CAPACITY  200  TONS,  10  HOURS,  SINGLE  STRAND 

HEAD 

1  Head-shaft  2r&  inches  by  48  inches  long 

2  Pillow-blocks  2^  inches  long. 

2     Collars  2/6-  inches }.  $15 . 20 

1     24-in.  No.  108  sprocket  wheel.' 

1     Key 

ELEVATOR   BOOT 

1     12"  X  7"  cast -iron  boot  complete  with  shafts,  adjustable 

boxes,  sprocket  wheels,  and  collars $42.00 

Price  per  foot  for  No.  108  chain  and  elevator  buckets 3.00 

CRUSHING  PLANT,  CAPACITY  250  TONS  DAILY 

1  44-inch  Class  A  disintegrator  complete $700 . 00 

Capacity  200  to  250  tons  daily.  Power  required,  1  horse- 
power for  every  4  or  5  tons  of  coal  crushed  daily.  Space 
occupied  by  disintegrator,  9  feet  by  6  feet. 

2  11"  X  18"  engines  connected  at  right  angles  with  two  60- 

inch  bandwheels  on  the  main  shaft  to  drive  to  the  two 
pulleys  on  the  disintegrator.  Engines'  speed,  150  revolu- 
tions per  minute,  developing  from  75  to  80  horsepower. 
Engines  are  complete  with  two  60"  X  12"  pulleys  on  the 
main  shaft,  automatic  stop-governor,  throttle  valve, 
spanner  wrenches,  cylinder,  lubricator,  oil  cups,  cylinder 
cocks,  anchor  bolts,  and  plates,  and  blueprint  drawings 
for  foundation.  Price  complete  as  described,  f.  o.  b. 
cars,  Aurora 738 . 00 

1  4-inch  tubular  boiler,  62  inches  diameter,  16  feet  long,  90 
horsepower,  complete  with  chimney  and  breeching,  guy 
rods,  fire-front,  grate  bars,  bearing  bars,  back  stand,  back 
plate,  soot  doors  and  frame,  anchor  bars,  tie-rods,  safety 
valve  and  weight,  check- valve,  stop-valve,  and  blow-off 
valve,  whistle,  water  and  steam  gauge,  feedpipe  and 
connections.  In  fact,  boiler  with  all  settings  and  trim- 
mings. Price  delivered  on  cars,  Aurora 895.00 

1  Duplex  pump  to  supply  boiler  with  water  and  all  fittings 

and  connections  to  connect  to  boiler 175. 00 

COST   OF   MACHINERY   AS   DESCRIBED 

1  44-inch  disintegrator  as  described $700 . 00 

2  11"  X  18"  double  engines,  75  to  80  horsepower 738.00 

1     4-inch  tubular  boiler,  62  inches  diameter,  16  feet  long,  90 

horsepower 895. 00 

1     Duplex  pump  as  described 175 . 00 

Total  cost $2,508 . 00 

ELEVATOR,  250  TO  275  TONS  CAPACITY  IN  10  HOURS, 
DOUBLE  STRAND 

HEAD 

1  Head-shaft  2^  inches  by  6  feet  long 

2  2re-inch  pillow-blocks 

2     2-iVinch  set  collars I          $21 . 50 

2     24-inch  No.  83  sprocket  wheels 

2     Keys 


TREATISE  ON  COKE  53 

ELEVATOR   BOOT 

1     14"  X  1"  cast-iron  boot  complete  with  shaft,  2  sprocket 

wheels,  adjustable  bearings  and  collars $47.00 

Price  per  foot  for  No.  83  double  chain  and  buckets 3.65 

CRUSHING  PLANT,  CAPACITY  350  TO  400  TONS  DAILY 

1  50-inch  coal  disintegrator  complete $  900  00 

Capacity  3"50  to  400  tons  of  crushed  coal  daily.  Power 
required,  1  horsepower  for  every  4  or  5  tons  crushed  coal 
in  10  hours.  Space  occupied  by  disintegrator,  10  feet  by 
8  feet;  weight  complete,  17,000  pounds. 

2  13"  X  20"  engines  complete,  connected  at  right  angles  with 

two  band  wheels  78  inches  diameter,  16-inch  face  on  the 
main  shaft  to  drive  the  two  pulleys  on  the  disintegrator. 
Engines  speed  at  140  revolutions  per  minute,  developing 
from  110  to  120  horsepower;  engines  complete  with  band- 
wheels,  automatic  stop-governor,  throttle  valve,  spanner 
wrenches,  cylinder  cocks,  lubricator,  oil  cups,  anchor 
bolts,  and  plates.  Blueprint  drawings  for  foundation 
furnished.  Price  complete,  f.  o.  b.  cars,  Aurora 1,000.00 

2  4-inch  tubular  boilers,  130  horsepower,  54  inches  diameter, 
14  feet  long,  complete  with  all  necessary  fittings  and 
trimmings,  consisting  of  fire-front,  grate  bars,  bearing 
bars,  back  plate,  soot  door  and  frame,  check,  blow-off 
and  stop-valve  whistle,  steam  gauge,  gauge-cocks,  water 
gauge,  chimney  and  breeching,  guy  rods,  safety  valve  and 
weight.  All  pipe  connections  between  engines  and  boilers 
are  extra.  Price  complete,  f.  o.  b.  cars,  Aurora 1,275.00 

1  Duplex  pump  to  supply  boilers  with  water  and  pipes  and 

fittings  for  same f  ......  1 50 . 00 

SUMMARY 

1  50-inch  disintegrator  complete  as  described $     900 . 00 

2  13"  X  20"  engines  as  described 1,000. 00 

2     Boilers,  130  horsepower,  54  inches  by  14  feet 1,275.00 

1     Duplex  pump  to  supply  boiler  with  water 150. 00 


Total $3,325.00 

ELEVATOR,  350  TO  400  TONS  CAPACITY,  10  HOURS 
DOUBLE  STRAND 


HEAD 


1  Head-shaft  2ff  inches  diameter,  5  feet  6  inches  long 
3  Pillow-blocks  2yf  inches  diameter 

2  Set  collars  2ff  inches  diameter 

2  25-inch  diameter  No.  108  sprocket  wheels 

2  Keys  for  wheels 


$30.00 


ELEVATOR  BOOT 


1      18"  X  18"  cast-iron  boot  complete  with  shaft,  two  No.  108 

sprocket  wheels,  adjustable  bearings  and  collars $60.00 

Cost  of  elevator  chain  and  buckets  per  running  foot 5.00 

ESTIMATE 

1  60-inch  class  A  coal  disintegrator,  complete  with  fly- 
wheels, pulleys,  etc.  Capacity,  500  tons  in  10  hours 
and  upwards.  Weight,  18,000  pounds $1,000.00 


54  TREATISE  ON  COKE 

2  14"  X  20"  engines  of  the  Houston,  Stan  wood  &  Gamble 
pattern,  coupled  at  right  angles  with  two  band  wheels 
84  inches  diameter,  16-inch  face  to  drive  the  belts 
running  direct  to  disintegrator,  engines  run  at  130 
revolutions  per  minute,  developing  about  125  to  135 
horsepower.  Engines  are  complete  with  governor,  two 
bandwheels,  throttle  valve,  spanner  wrenches,  automatic 
sight-feed  lubricator,  oil  cups,  and  cylinder  cocks.  All 
pipe  fittings  and  connections  are  extra.  Price  of  engine 
as  described $1,064.00 

2  Tubular  boilers  60  inches  diameter,  10  feet  long;  rated  at 
160  horsepower,  complete  with  all  necessary  trimmings, 
consisting  of  fire-front,  grate  bars,  bearing  bars,  back 
plate,  soot  door  and  frame,  check,  blow-off  and  stop- 
valve,  whistle,  steam  gauge,  gauge-cocks,  water  gauge, 
chimney  and  breeching,  guy  rods,  safety  valve  and 
weight  All  pipes  and  connections  between  engines  and 
boilers  are  extra.  Price  complete,  f.  o.  b.  cars,  Aurora  1,650.00 

1  Duplex  pump  to  supply  boiler  with  water  and  pipe  and 

fittings  for  same 1 75 . 00 

SUMMARY 

1  60-inch  disintegrator  complete  as  described $1,000 .00 

2  14"  X  20"  engines  as  described 1,064  00 

2  Boilers  160  horsepower  as  described 1,650. 00 

1     Pump  to  feed  boiler 175.00 

Total $3,889.00 

ELEVATOR,  550  TONS  CAPACITY 

HEAD 

1     Head-shaft  3i^  inches  diameter,  6  feet  long 

3  Pillow-blocks  3r^  inches  diameter . . 


2     Collars  3-^  inches  diameter >          $41 .00 

2     30-inch  No.  108  sprocket  wheels 

2     Keys 

ELEVATOR   BOOT 

1     Cast-iron  boot  for  24"  X  10"  buckets  complete  with  shaft, 

two  sprocket  wheels,  adjustable  bearings  and  collars .  .  .  $75 . 00 
Price    per   foot    for    No.    108   double    elevator   chain    and 

buckets , 6. 50 

Link-Belt  Coal  Breaker. — The  coal  breaker,  Fig.  4,  is  made  by 
the  Link-Belt  Machinery  Company,  Chicago,  Illinois. 

The  size  and  spacing  of  the  teeth  are  made  to  suit  the  size  to 
which  the  coal  is  to  be  broken,  by  which  is  meant  the  size  of  the 
largest  pieces.  In  breaking  to  this  size  a  large  part  will  be  broken 
finer.  In  general,  it  may  be  expected  that  the  smaller  the  diameter 
of  the  roll  the  greater  will  be  the  percentage  of  fine,  so  that,  if  it  is 
desired  to  break  to  a  certain  size  without  reducing  much  to  smaller 
size,  large  diameters  of  rolls  should  be  selected  or  a  series  of  rolls 
put  in,  breaking  first  coarse,  then  finer,  with  screens  between. 

These  rolls  are  made  in  the  following  sizes: 


TREATISE  ON  COKE 


55 


Size  of  Rolls 

Shipping 
Weight 

Approxi- 
mate 
Capacity 

Speed 
Revolu- 
tions 

Horse- 
power 

Maximum  Size 
of  Piece  That 
Will  Enter 

Diameter 

Length 

Pounds 

Tons 
per  Hour 

per 

Minute 

Required 

Inches 

15 

20 

3,500 

10 

225 

10 

10X15 

18 

24 

5,550 

20 

200 

12 

10X20 

24 

24 

7,000 

25 

160 

15 

14X20 

24 

30 

7,800 

35 

160 

20 

14X24 

28 

30 

10,000 

40 

125 

25 

16X24 

28 

36 

12,000 

50 

125 

35 

16X30 

30 

36 

13,000 

75 

100 

40 

18X30 

FIG.  4.    LINK-BELT  COAL  BREAKER 


FIG.  5.     LINK-BELT  COAL  CRUSHER 


Fig.  5  shows  a  crusher  made  by  this  company  and  having  one 
smooth  and  one  corrugated  roll.  It  is  used  for  special  service  in 
coal  washing. 


56 


TREATISE  ON  COKE 


Fig.  6  shows  a  disintegrator  made  by  the  same  company  and 
used  for  fine  crushing  of  coal.  It  is  made  in  two  sizes:  36-inch 
diameter,  20-inch  face;  48-inch  diameter,  24-inch  face. 


COAL  WASHING 

Coal  washing  is  entirely  a  mechanical  process,  and  water  is  the 
main  element  employed  in  separating  the  coal  from  its  impurities. 
The  chief  requirement  in  the  coal-washing  process  is  the  reduction 


FIG.  6.     LINK-BELT  DISINTEGRATOR 

of  the  sulphur  in  its  several  conditions  and  of  the  ash,  so  that  the 
coke  made  from  this  washed  coal  shall  contain  under  1  per  cent. 
of  sulphur,  with  ash  from  6  to  10  per  cent.  This  operation  for  the 
successful  cleansing  of  the  coal  depends  on  the  enabling  law  of 
the  difference  of  the  specific  gravities  of  the  coal  and  its  several 
impurities.  The  average  specific  gravities  of  these  are: 

SPECIFIC  GRAVITY 

Water 1 . 00 

Coal 1 . 25  to  1 . 50 

Bone  coal 1.45  to  1.80 

Slate 2.25  to  2. 50 

Coal  or  slate  with  pyrites 3.20  to  3.60 

Pyrites 5.00  to  5. 20 

In  practice,  a  great  variety  of  the  combinations  of  these  elements 
is  found  in  the  coal,  requiring  in  its  preparation  for  the  washer 
and  in  the  washing  process  special  treatment  for  each  variety. 

As  has  been  noted,  the  coal  requires  a  preparation  for  washing 
by  crushing  or  breaking  and  by  classifying  or  sizing.  Whether  the 
coalis  to  be  used  in  the  manufacture  of  coke  or  for  any  other 
purpose,  the  sizing  of  the  coal  in  its  preparation  for  washing  is 
indispensable.  It  has  been  determined  that,  as  a  general  rule,  the 


TREATISE  ON  COKE 


57 


smaller  the  ratio  of  reduction  of  the  pieces  of  the  coal,  the  more 
complete  is  the  process  of  separation.  Very  much,  therefore,  of 
the  success  of  this  operation  depends  on  the  proportioning  of  the 
sizes  of  the  meshes  in  the  classifying  screens,  especially  for  the 
separating  of  the  lesser  impurities  in  the  coal  under  the  grosser 
iron  pyrites,  which  are  the  most  readily  removed. 

It  may  be  noted  here  that  the  best  machinery  for  accurate 
separation  or  cleansing  of  the  coal  is  usually  the  most  costly, 
involving  the  greater  expense  in  the  first  cost  of  the  plant,  but 
securing  in  its  work  the  best  results.  As  will  be  seen  hereafter,  in 
the  preparation  of  the  washed  coal  for  charging  into  the  coke 
oven,  the  coal-storage  arrangement  to  remove  some  of  the  water 
or  moisture  from  the  coal  is  a  secondary  necessity. 


TROUGH  WASHERS 

Simple  Trough  Washer. — During  the  close  of  the  past  century, 
especially  in  continental  Europe,  very  much  attention  was  given 
to  mechanical  appliances  for  washing  coal.  The  most  primitive  of 
these  consisted  in  a  long  wooden  trough,  divided  by  low  cross- 
sectional  dams  at  intervals  along  its  course.  The  inclination  of 
this  sluice  was  usually  made  to  give  sufficient  force  to  the  water 
passing  through  it  to  separate  the  coal  from  the  slate,  the  slate 
remaining  in  the  upper  recesses  of  the  dams,  while  the  coal  was 


FIG.  7.     PLAN  AND  SECTION  OF  TROUGH  WASHER 

t,  trough;  s,  dams;  a,  screen;  h,  hopper  for  delivery  of  coal;  p,  stand  pipe  for  applying 
water;  c,c' ,  cars  for  washed  coal  and  slates;  this  wooden  trough  is  usually  30  to  100  feet  long, 
2  to'4  feet  wide,  and  12  to  15  inches  deep. 

carried  over,  screened,  and  delivered  into  a  car  or  other  receptacle 
at  the  lower  end  of  the  sluice.  The  slate  was  removed  at  stated 
intervals  by  an  attendant  with  a  rake.  The  prepared  coal  and 
the  water  for  its  cleansing  were  received  together  at  the  upper  end 
of  the  trough.  The  plan  and  section,  Fig.  7,  will  make  this  old- 
time  washer  and  its  operations  easily  understood. 


58 


TREATISE  ON  COKE 


TREATISE  ON  COKE  59 

Elliott  Trough  Washer. — An  improvement  has  been  made  on 
this  trough  washer,  which  adds  very  much  to  its  efficiency,  econo- 
mizing labor  and  water  in  the  process  of  washing.  The  following 
plan,  section,  and  description,  Fig.  8,  are  taken  from  The  Colliery 
Guardian,  London,  of  November  16,  1894.  This  machine  was 
designed  on  the  lines  of  the  old  trough  washer,  which  has  long  been 
a  favorite  with  many  colliery  engineers  on  account  of  its  sim- 
plicity and  its  efficiency  when  in  the  hands  of  an  intelligent,  trust- 
worthy attendant.  In  addition  to  the  difficulty  of  always  obtaining 
the  necessary  skill  and  attention,  there  was  also  in  the  old  troughs 
the  necessity  of  changing  the  flow  of  coal  and  water  into  a  second 
trough  while  the  dirt  was  being  washed  off  and  removed  from  the 
first,  when  the  stops  had  become  charged  with  it;  for  if  this  was 
not  done  at  the  proper  time  some  of  the  dirt  became  mixed  with  the 
coal  and  the  result  was  not  satisfactory.  The  Elliott  washer,  as 
shown  in  Fig.  8,  is  claimed  to  be  automatic  in  its  action,  and  retains 
all  the  advantages  of  economy  and  efficiency  of  the  old  trough 
without  any  of  its  disadvantages;  it  is,  moreover,  independent  of 
the  skill  or  attention  of  the  attendant,  the  operation  of  washing 
proceeding  without  interruption  as  long  as  is  required,  the 
coal  being  delivered  at  one  end  of  the  trough,  with  the  water 
and  the  dirt  at  the  opposite  end. 

The  washer  is  constructed  with  a  wrought-iron  or  steel  trough 
about  18  inches  wide,  having  sloping  sides,  being  widest  apart  at 
the  top,  and  narrowest  at  the  bottom.  At  each  end  of  this  trough 
is  fixed  a  sprocket  wheel,  on  which  rides  a  chain,  attached  to  which, 
at  suitable  distances  and  at  right  angles  to  it,  are  scrapers  that 
correspond  to  the  inside  shape  of  the  trough.  The  scrapers  form 
movable  stops,  or  dams,  that  are  slowly  moved  by  the  chain  along 
the  trough  in  the  opposite  direction  to  the  way  the  water  runs. 
The  trough  is  fixed  at  a  suitable  inclination,  and  the  coal  is  admitted 
at  the  center  of  its  length  and  the  water  at  its  highest  end  or  there- 
abouts, and  as  it  runs  to  the  lowest  end  it  carries  with  it  the  coal, 
which  is  lighter  than  the  dirt;  the  dirt  settles  in  the  scrapers  and 
is  conveyed  by  them  against  the  stream  of  water  and  delivered  at 
the  opposite  end  to  that  at  which  the  coal  escapes.  The  speed  of 
the  scrapers  and  quantity  of  water  are  regulated  to  suit  the  material 
washed.  The  water  is  circulated  and  used  continuously,  so  that 
the  waste  is  only  that  which  is  carried  away  by  the  dirt  and  coal 
after  drainage.  A  centrifugal  or  other  pump  is  used  for  elevating 
the  water  to  the  washer.  The  arrangement  for  draining  the  water 
from  the  coal  is  such  that  there  is  no  waste  of  coal  or  pollution  of 
streams,  etc.  A  1-inch  pipe  will  keep  good  the  supply  of  water 
for  each  trough,  or  100  tons  of  coal  washed  per  day.  This  washer 
has  been  introduced  by  the  Hardy  Patent  Pick  Company,  Limited, 
of  Sheffield,  England. 

This  class  of  coal  washer  requires  large  quantities  of  water,  and 
its  work  is  somewhat  expensive  and  imperfect. 


(a)     Trough  Raised 


FIG.  9.     SCAIFE  TROUGH  WASHER 


TREATISE  ON  COKE  •      61 

The  Scaife  trough  washer,  Fig.  9  (a)  and  (6),  consists  of  an 
inclined  trough  a  of  semicircular  cross-section,  2  feet  in  diameter 
and  24  feet  long,  provided  at  intervals  with  riffles.  Lengthwise 
of  the  trough  is  the  shaft  b  to  which  are  attached  the  stirrers  c. 
The  shaft  is  given  a  reciprocating  motion  by  means  of  an  arm  in 
its  center,  worked  by  a  connecting-rod  attached  to  the  flanged 
driving  pulley  d.  The  empty  trough,  which  is  hinged  to  the  frame 
on  one  side,  is  partly  held  in  position  by  the  adjustable  counter- 
balance weights  e  on  the  arms  /  attached  to  the  trough.  A  tongue 
on  the  operating  lever  g  passes  through  an  eye  on  the  trough  and 
firmly  holds  it  in  place. 

Coal  and  water  are  fed  into  the  upper  end  of  the  trough  a.  The 
combined  action  of  the  flowing  water  and  stirrers  causes  the  slate 
and  other  impurities  to  settle  at.  the  bottom  of  the  trough,  where 
they  are  caught  by  the  riffles,  while  the  clean  coal  passes  over  the 
top  and  out  at  the  lower  end.  When  the  spaces  between  the  riffles 
are  filled  with  impurities,  the  feeding  of  coal  is  stopped,  or  tempo- 
rarily turned  into  an  adjacent  washer,  and  all  the  remaining  coal  is 
washed  over  the  riffles.  The  operating  lever  g  is  moved  a  few 
inches  to  the  right,  which  draws  the  steel  tongue  out  of  the  eye  and 
releases  the  trough,  and  allows  the  latter  to  drop  and  dump  the 
refuse.  The  trough  is  returned  to  its  original  position  by  moving 
the  operating  lever  still  farther  to  the  right,  which  engages  a  clutch 
and  causes  the  chain  h  to  be  wound  up  and  lift  the  trough;  the 
weight  i  keeps  the  chain  taut.  As  soon  as  the  trough  is  raised,  the 
lever  should  be  drawn  quickly  to  the  left  until  it  reaches  its  original 
position.  This  movement  releases  the  clutch  and  locks  the  tongue 
in  the  supporting  eye  of  the  trough.  The  washing  is  then  recom- 
menced. Where  the  washer  is  properly  erected  and  operated, 
the  dumping  and  raising  will  occupy  less  than  a  minute.  This 
washer  has  no  screen  to  wear  and  be  replaced.  The  principal 
wearing  parts  are  the  stirrers,  which  are  inexpensive  and  can,  if 
desired,  be  made  anywhere.  The  water  may  be  used  over  and 
over  again.  The  slope  or  fall  given  to  the  trough  depends  on  the 
size  of  the  coal  and  nature  of  the  impurities;  the  larger  the  coal, 
the  greater  should  be  the  slope  and  the  quantity  of  water. 


JIGS 

Principle  of  the  Jig. — To  economize  water  and  separate  the 
impurities  from  the  coal  in  a  more  complete  and  economical  manner, 
an  improved  class  of  washing  machines,  called  jigs,  has  been  intro- 
duced. These  have,  in  a  great  measure,  displaced  the  older  meth- 
ods. The  several  classes  of  the  broken  coal  previously  sized  are 
delivered  into  separate  receptacles,  or  jigs,  in  a  water  bath,  and 
the  separation  of  the  coal  from  the  impurities  is  accomplished  by 
imparting  a  pulsing  motion  to  each  receptacle,  or  jig,  of  such  speed 
as  to  secure  the  best  results.  This  pulsing  motion  in  the  modern 


62 


TREATISE  ON  COKE 


improved  machines  forces  the  lightest  matter — the  coal — to  the 
surface  of  the  water,  carrying  it  forwards  and  over  the  delivering 

edge  of  the  jig  into  a  car  or 
other  means  of  conveyance  to 
move  it  to  points  where  it  is  to 
be  used.  The  heavier,  or  im- 
pure, matters  sink  under  the  coal 
in  this  pulsing  movement  and 
are  dropped  into  special  receiv- 
ers under  the  washer  for  ulti- 
mate disposition. 

The  force  of  the  upward 
pulsing  current  is  regulated  so 
as  to  meet  the  requirements  of 
the  several  varieties  of  coals, 
in  the  process  of  removing  their 
impurities.  If  this  current  is 
too  strong  it  will  disarrange  the 
classification  of  the  coal;  if  too 


FIG 


HARTZ  JIG 


w, 


p,    plunger;    /,    feeder,  prepared  coal; 
water  supply;  s,  water  chamber;  o,  coal  cham- 
her;   a,  slate  delivery;    b,  clean-coal  discharge; 

f,  sludge  discharge. 

Capacity,   about  150  tons  per  day.     Cost, 

about  5  cents  per  ton. 


it  will  fail  to  separate  the 
larger  pieces  of  coal.  It  is  also 
important  that  the  force  of  the 
upward  pulsing  current  be  uni- 
form in  its  action  through  the  mass  of  coal  in  the  washer  chamber 
of  the  apparatus,  otherwise  imperfect  work  will  ensue. 

Mr.  H.  Rittinger,  who  has  given  the  mechanical  separation  of 
materials  considerable  study, 
has,  from  practical  tests,  de- 
duced the  following  formula: 
The  velocity  of  the  current 
in  feet  per  second  is  equal  to 
1.28  ^D(d—l),  in  which  d  is 
the  density  of  the  material, 
and  D  the  diameter  of  the 
meshes  in  the  screen,  or  prac- 
tically the  diameter  of  the 
pieces  to  be  operated  on. 


The    Hartz    Jig.— Fig.    10 

illustrates  the  general  princi- 
ples of  the  operations  of 
this  class  of  coal-washing 
machines. 


FIG.  11.     LUHRIG  FELDSPAR  JIG 


The  Liihrig  jig,  Figs.  1 1  and 
12,  illustrates,  in  a  brief  way, 
the  essential  elements  of  coal  washing.     Fig.  11  shows  the  Liihrig 
feldspar  jig,  which  is  used  exclusively  for  the  treatment  of  fine  coal. 


TREATISE  ON  COKE 


63 


Fig.  12  shows  the  Liihrig  nut-coal  jig  as  arranged  with  its  machinery 
for  automatically  removing  the  refuse. 

Berard's  coal-washing  machine,  Fig.  13,  was  introduced  in 
London  in  1851,  and  in  Paris  in  1855.  It  was  used  by  the  Kemble 
Coal  and  Iron  Company  in  the  Broad  Top  region,  Pennsylvania, 
for  a  few  years  beginning  in  1873. 

The  coal  to  be  cleaned  is  dumped  from  the  railroad  car  a  into 
the  hopper  b  by  a  side  door  over  an  iron  chute;  thence,  it  is  diffused 
on  the  separator  c,  which  is 
kept  in  agitation  by  the  cam  d. 
The  lumps  that  will  not  pass 
through  the  3-inch  square 
openings  in  c  roll  down  to  the 
screen  platform  e,  where  they 
are  broken  by  a  workman 
with  a  maul  and,  falling 
through  the  grating,  pass  to 
the  rolls  /.  The  smaller  lumps 
pass  through  the  3-inch 
meshes  in  the  agitator  screen 
c,  when  they  are  further 
divided  by  a  screen  under- 
neath c.  The  portions  of 
the  coal  that  will  not  pass 
through  the  J-inch  holes  in 
the  latter  screen  pass  directly 
to  the  rolls  /,  while  the  very 
fine  portion  is  carried  under 
the  rolls,  down  the  chute  g, 
into  the  receiver  h.  The 
rolls  /  have  teeth,  or  spurs, 
set  all  over  their  circumfer- 
ence, each  being  about  J  inch 
square  by  ^  inch  high.  Their  arrangement  is  such  that  the  spurs 
of  one  roll  mesh  into  those  of  the  other.  One  of  the  crushing 
rolls  has  its  pillow-blocks  set  with  a  rubber-ball  spring,  so  as  to 
admit  a  small  horizontal  movement,  to  prevent  the  breaking  of 
the  teeth  of  the  rolls  by  the  passage  of  hard  slates  or  pyrites. 

After  passing  the  rolls,  the  crushed  coal  falls  into  the  receiver  h, 
whence  it  is  elevated  by  the  chain  of  buckets  i  and  delivered  into 
the  chutes  /,  through  which  it  is  carried  into  the  separating  pans  k, 
which  are  made  of  cast  iron,  with  a  copper  plate  on  top  of  the 
grating,  forming  the  bottom  of  the  iron  pan;  the  copper  plate  is 
perforated  with  J-inch  holes,  set  close  together.  The  pans  are 
supplied  with  water  conveyed  by  troughs,  through  which  the  coal 
is  also  carried.  The  action  of  the  piston  /,  which  moves  with  quick, 
short  strokes  (120  per  minute),  forces  the  water  through  the  coal 


FIG.  12.     LttHRic  NUT-COAL  JIG 


64 


TREATISE  ON  COKE 


TREATISE  ON  COKE  65 

and  slate  in  rapid  pulsations,  lifting  the  pure  coal  upwards  and 
onwards  with  the  movements  of  the  water  until  it  is  carried  over 
the  side  of  the  pan  at  m,  and  thence  over  a  grated  chute  into  the 
car  n,  on  the  track  in  front  of  the  washer. 

The  impurities,  being  heavier  than  coal,  sink  to  the  bottom  of 
the  pan  and  are  carried  to  its  front  interior  angle,  whence  they  are 
discharged  by  a  valve  o  into  the  receiver  p,  from  which  they  can  be 
removed  by  a  sliding  bottom  q.  The  movement  of  the  mass  of 
coal  in  the  pan  is  about  20  inches  per  minute,  giving  a  continuous 
overflow  of  washed  coal  into  the  receiving  cars  below.  This  flow 
can  be  regulated  by  raising  or  lowering  the  front  side  of  the  wash 
pan  at  m. 

The  main  portion  of  the  water  in  the  washed  coal  is  drained 
from  it  by  a  fine  copper-wire  screen  on  a  chute,  immediately  under 
the  discharge  from  the  wash  pan  at  m.  This  water,  charged  with 
the  very  fine  coal  and  dust,  passes  through  r,  and  is  conveyed  by 
a  trough  s  into  a  large  tank  alongside  the  washer,  where  the  fine 
coal  is  permitted  to  settle,  and  from  which  it  is  shoveled  into  the 
receiving  cars  along  with  the  coarser  coal  and  all  charged  into 
the  coke  ovens. 

The  Stutz  improved  coal  washer,  Fig.  14  (a)  and  (b),  has  been 
tested  in  practice  during  many  years.  It  is  simple  in  its  construc- 
tion, yet  efficient  in  its  operations,  requiring  a  small  force  in  working 
it.  It  was  designed  by  S.  Stutz,  mining  and  mechanical  engineer, 
of  Pittsburg,  Pennsylvania,  who  has  followed  up  its  workings, 
adding  from  time  to  time  such  improvements  as  appeared  neces- 
sary to  make  its  processes  more  complete. 

Fig.  14  (a)  is  a  longitudinal  vertical  section,  and  Fig.  14  (b)  a 
vertical  cross-section  at  the  lines  XX  and  Z Z  of  Fig.  14  (a). 

In  this  figure,  a,  a  are  cast-iron  brackets  supporting  a  rectan- 
gular box  divided  into  chambers  b,  c,  and  d,  constituting  two 
complete  machines.  Arranged  within  the  chamber  b  is  a  screen 
or  sieve  e,  while  the  chamber  c  contains  the  piston,  or  plunger,  / 
with  its  mechanism  to  reciprocate  vertically.  The  slate  chamber  d 
communicates  with  the  separating  or  washing  chamber  b  through 
an  opening  g,  governed  by  a  suitable  valve  h. 

A  trough,  or  chute,  i  provided  with  a  screen  /  communicates 
with  the  separating  chamber  b  to  receive  the  washed  coal  as  it 
passes  over  the  bridge  k.  Beneath  the  slate  chamber  d  and  the 
separating  chamber  b  an  auxiliary  receiver  /  is  arranged,  which 
communicates  with  both  chambers  by  means  of  the  openings  m' 
and  m,m,  for  the  purpose  of  providing  means  to  collect  the  sedi- 
ment that  passes  through  the  meshes  of  the  sieve  e  during  the 
operation  of  the  machine,  and  to  effect  its  escape  without  wasting 
the  water  in  the  washing  chamber  6,  thus  making  the  operation  of 
the  washer  continuous.  Before  letting  out  the  fine  sediment,  the 
openings  m,  m  are  closed  by  the  gates  n,  n,  and  the  communication 


G6 


TREATISE  ON  COKE  67 

with  the  washing  chamber  b  is  shut  off.  No  water  is  wasted.  The 
receiver  also  collects  the  coarse  impurities  from  the  slate  chamber  d ; 
both  kinds,  coarse  and  fine,  may  be  let  to  the  outside  of  the  machine 
by  the  levers  o,  o' . 

The  piston,  or  plunger,  /  is  provided  with  large  openings  p,  p, 
in  its  bottom;  they  are  governed  by  floating  valves  q  underneath, 
kept  in  proper  position  by  guides  r,  r.  With  the  improved  plunger, 
the  necessary  volume  of  water  is  let  into  the  machine  from  above 
by  means  of  the  pipe  s,  thus  filling  up  more  easily  the  entire  space 
when  the  piston  is  moving  upwards.  Movement  is  imparted  to 
the  latter  from  the  shaft  t  by  means  of  the  cam  u,  yoke  v,  and 
rod  w.  Coal  to  be  washed  is  supplied  to  the  screen  e  through  a 
hopper  x.  The  separation  of  the  coal  from  its  impurities  is  accom- 
plished in  the  usual  way.  The  pulsations  of  the  water  by  the 
movements  of  the  plunger  lift  the  lighter  coal  upwards,  while  the 
slates,  pyrites,  etc.  sink  to  the  bottom.  The  stroke  of  the  plunger 
can  be  varied  to  meet  the  wants  of  the  different  sizes  of  coal. 

The  Stutz  improved  coal-jigging  and  washing  machine,  Fig.  15, 
has  a  vertical  reciprocating  piston  or  plunger  directly  underneath 
the  stationary  sieve  or  screen;  (a)  is  a  longitudinal  vertical  section 
through  the  center  of  the  jigger;  (b)  is  a  section  taken  at  line  X  X 
of  the  top  view  (c),  and  a  front  elevation  of  two  machines  combined 
together. 

In  the  figure,  a,  a  represent  cast-iron  brackets  supporting  the 
separating  box  b,  arranged  within  which  is  the  screen  or  sieve  e, 
with  the  piston,  or  plunger,  /  below,  and  the  mechanism  whereby 
the  latter  is  caused  to  reciprocate  vertically  above.  The  slate 
chamber  d  communicates  with  the  washing  chamber  b  through  the 
opening  g,  governed  by  the  valve  h.  A  trough  or  channel  i  also 
communicates  with  the  washing  chamber  b  and  is  designed  to 
receive  the  washed  coal  as  it  comes  over  the  delivery  bridge  k.  An 
auxiliary  receiver  /  is  arranged  beneath  the  chamber  6,  and  com- 
municates with  the  latter  by  means  of  openings  m,  m  governed 
by  gates  n,  n.  The  receiver  /  also  communicates  with  the  slate 
chamber  d,  through  the  opening  m',  for  the  passage  of  the  coarse 
impurities.  The  outlet  gate,  or  door,  y  of  the  auxiliary  receiver 
is  connected  to  bell-crank  levers  o,  o  by  links.  Movement  is 
imparted  to  piston  /  by  means  of  eccentrics  u,  u  keyed  upon  the 
driving  shaft  t,  and  yokes  v,  v  connected  to  rods  z,  z.  Coal  is  fed 
upon  the  screen  e  from  the  hopper  x,  while  the  supply  pipe  s  fur- 
nishes the  necessary  volume  of  water  for  the  operation. 

The  purpose  of  the  auxiliary  receiver  /  is  to  provide  means  for 
collecting  the  fine  sulphur  and  slate  pieces  that  pass  through  the 
meshes  of  the  sieve  e  during  the  working  of  the  machine,  and  to 
effect  the  escape  of  this  fine  sediment  without  wasting  the  water 
inside  the  washing  chamber  b,  thus  making  the  operation  of  the 
jigger  absolutely  continuous. 


68 


TREATISE  ON  COKE 


By  means  of  the  improved  and  special-shaped  piston  /  acting 
at  each  up  stroke  like  a  wedge  behind  the  material  on  the  screen, 
the  different  layers  of  the  separated  substances — coal  and  impuri- 


ties—-are  readily  and  uniformly  advanced  toward  the  delivery 
openings,  while  below  the  screen  the  rilling  up,  or  choking,  by  the 
fine  sediment  passing  through  its  meshes,  is  also  prevented. 


TREATISE  ON  COKE 


69 


The  cost  of  these  coal-washing  machines,  for  cleaning  300,  400, 
and  600  tons  per  day,  will  depend  mainly  on  location,  quality  of 
coal  to  be  treated,  and  the  character  of  its  impurities.  Mr.  Stutz 
has  furnished  estimates  for  the  treatment  of  the  above  outputs 
per  day  of  10  hours  at  $11,000,  $13,000,  and  $16,000,  respectively. 
This  estimate  includes  the  necessary  power,  water,  and  building. 
It  does  not,  however,  embrace  the  machine  for  disintegrating 
the  coal  in  the  preparatory  process;  the  cost  of  this  will  be  found 
under  the  head  of  coal  crushers  or  disintegrators.  The  cost  of 
washing  is  given  at  2  cents  per  ton  for  the  work  of  washing  alone. 


FIG.  16.     STEIN'S  STANDARD  COARSE  CORN-COAL  JIG,  STYLE  C 

The  interest  on  investment  of  plant  and  the  wear  and  repair  of 
machinery  must  be  added  to  show  the  total  cost  of  cleaning  the 
coal  in  this  machine. 


WALTER  M.  STEIN'S  WASHERS 

Stein  Jigs. — Figs.  16,  17,  and  18  show  jigs,  Stein  standard, 
while  Fig.  19  shows  the  general  arrangement  of  a  coal-washing 
plant  designed  by  Mr.  Walter  M.  Stein,  of  Philadelphia,  for  the 
New  Glasgow  Iron,  Coal,  and  Railroad  Company,  of  Nova  Scotia. 


70 


TREATISE  ON  COKE 


The  coal  from  the  various  mines  arrives  on  the  railroad  tracks 
olf  a2  and  is  dumped  into  the  pits  6lf  62  underneath,  a  different  kind 
in  each  pit.  From  these  pits,  the  coal  is  taken,  by  means  of  bucket 
elevators  clt  c2,  to  the  shaking  screen  d.  This  shaking  screen  has 
a  double  eccentric  motion,  imitating  hand  screening  as  much  as 
possible.  The  mesh  of  the  screen  plate  is  |  inch.  The  material 
too  large  to  pass  through  the  perforations  drops  into  the  crusher 


FIG.  17.     STEIN'S  JIG  FOR  COARSE  SIZES,  STYLE  G  STEIN'S  JIG  FOR  FINE  SIZES,  STYLE  H 

WOOD  OR  IRON  TANKS 

rolls  elt  e2,  and  is  again  taken,  after  the  crushing,  to  the  shaking 
screen  d  by  means  of  the  bucket  elevator  /.  The  coal  passing 
through  the  shaking  screen  d  is  taken  by  means  of  the  bucket 
elevator  g  to  the  separating  screen  drum  h,  which  separates  it  into 
three  sizes — 0  to  J  inch,  J  to  J  inch,  and  J  to  f  inch. 

The  different  sizes  are  carried  by  means  of  chutes  to  the  various 
jigs  j\  to  /8.  These  are  all  two-compartment  feldspar  jigs,  arranged 
with  variable  stroke.  Each  screen  compartment  is  28  inches  wide 
and  49  inches  long,  so  that  the  coal  must  travel  a  distance  of  over 
8  feet  while  being  washed.  The  washed  coal  flows  in  gutters  to 
the  large  elevator  boot  &2,  and  is  elevated  from  there  to  the  top  of 
the  storage  tower  by  means  of  the  perforated  bucket  elevator  /2, 
which  discharges  on  the  distributing  conveyer  m,  which  carries  it 
into  the  various  compartments  n  of  the  large  storage  tower.  The 
two  jigs  shown  in  dotted  lines,  the  elevator  boot  klt  and  the  eleva- 
tor /!,  are  arranged  to  be  put  in  if  the  plant  requires  enlargement. 
The  slate  from  jigs  j\  to  /3  is  discharged  into  elevator  boot  qlt  and 
is  taken  from  there  by  means  of  a  perforated  bucket  elevator  rv 
and  dumped  into  railroad  cars  ready  to  be  taken  to  a  convenient 
dumping  place.  The  centrifugal  pump  /  distributes  the  water, 
which,  after  being  used,  always  returns  to  the  pump  and  is  used 
over  again.  There  is  no  loss  in  this  respect  except  that  absorbed 
by  the  coal,  and  enough  fresh  water  must  be  added  to  make  up 
for  this,  u  is  the  steam  engine  of  100  horsepower  to  drive  the 
entire  plant. 


17303— in 


FIG.  19.     COAL-WASHING  PLANT  OF  NEW  GLASGOW 


-Sect/on  £-f 
v,  COAL,  AND  RAILROAD  COMPANY,  OF  NOVA  SCOTIA 


TREATLSE  ON  COKE 


71 


All  the  elevators  are  of  special  construction  and  have  very 
large  buckets,  automatic  feed,  etc.,  and  are  run  at  a  slow  speed. 

The  entire  plant  works  automatically,  requiring  only  three  men 
to  operate  it.  The  coal  before  washing  contains  from  17  to  35  per 
cent,  of  ash,  besides  about  2^  to  3  per  cent,  of  sulphur;  the  washed 
coal  contains  in  the  average  10  per  cent,  of  ash  or  1  per  cent,  more 
than  the  fixed  ash,  9  per  cent. ,  of  the  coal.  This  is  a  remarkably  good 
showing,  and  is  seldom  equaled  at  any  washing  plant  in  existence. 
The  fixed  ash  cannot  be  reduced  by  any  method.  Coming  within 
2  per  cent,  of  the  fixed  ash  is  ordinarily  considered  excellent  work. 
The  sulphur  is  reduced,  by  washing,  from  2J  to  3  per  cent,  down 
to  1.35  per  cent.,  that  still  left  being  the  organic  sulphur  and  that 
in  combination  with  alumina  or  lime. 

Jigs  yt  to  ;5  were  in  the  original  plant ;  /6  to  /8  were  added  when 
the  additional  retort  coke  ovens  were  built.  The  total  capacity 
of  the  plant  is  now  300  tons  of  coal  in  10  hours. 


FIG.  18.     STEIN'S  FINE  CORN-COAL  JIG,  STYLE  A,  Two  COMPARTMENTS,      > 
AUTOMATIC  SLATE  VALVE 

The  Diescher  coal  washer,  Fig.  20,  may  be  constructed  with  one 
box  or  with  a  number  of  boxes  connecting  with  each  other  and 
worked  by  the  same  shaft.  The  boxes  may  either  have  outlets,  as 
shown  in  (d)  and  on  plan  (a),  with  an  elevator  for  carrying  away 
the  slate  and  other  deleterious  materials,  or,  where  the  boxes  are 
fixed  on  elevated  ground,  they  may  have  pyramidal  receptacles 


72 


TREATISE  ON  COKE 


into  which  such  material  falls  and  is  discharged  at  intervals  by  its 
own  gravity  through  a  valve  operated  by  a  lever. 

The  modus  operandi  of  the  washer  is  as  follows:  The  coal  is 
dumped  from  the  back  upon  the  screen  shown  in  section  in  views 
(c)  and  (d) ;  the  water  is  conveyed  to  the  washer  by  a  3-inch  pipe 
entering  into  a  cast-iron  box  fixed  at  the  back  (a) ;  this  box  runs 
along  the  back  of  the  washer  below  the  screen  and  delivers  the 
water  through  four  2-inch  holes  cut  out  of  the  washer  side  (a)  and 
(c).  The  action  of  the  plunger  forces  the  water  through  the  screen, 


rw 

(a)  Plan     (6)  £nrf  Elevation      (c)  Longitudinal  Section     (d)   Transverse  Section 
FIG.  20.     DIESCHER  COAL  WASHER 

agitating  the  coal  and  carrying  the  cleaned  coal  over  the  wooden 
ledge,  shown  to  the  left  and  a  little  above  the  screen,  into  a  trough 
that  conveys  it  into  bins;  the  slate  and  other  heavy  and  delete- 
rious materials,  by  force  of  their  greater  specific  gravity,  fall  to 
the  screen  and  escape,  through  the  valve  shown,  into  the  discharge 
pipe  and  elevator,  or  into  the  box  previously  referred  to. 

The  washer  is  constructed  as  shown  in  the  figure,  having  two 
cast-iron  stanchions  of  H  section  footed  out  at  the  bottom  as  shown. 
The  upper  part  of  the  stanchion  has  9-inch  web  with  4-inch  flanges, 
by  about  f -inch  metal.  The  stanchions  are  connected  together  on 
top  by  means  of  two  girders  of  similar  section  but  arch-backed, 


TREATISE  ON  COKE 


73 


having  the  central  part  of  top  flange  level  and  dovetailed  to  receive 
the  bearing  for  the  main  shaft.  The  stanchions  are  kept  rigid  by 
means  of  two  l}-inch  wrought-iron  tie-bolts  and  distance  pieces 
of  pipe  [see  top  of  stanchion  in  view  (d)],  and  the  girders  are  bolted 
to  the  ends  of  the  stanchion  by  four  wrought-iron  bolts  at  each  end. 
The  body  of  the  washer  is  composed  of  4-inch,  white-pine  tim- 
bers of  the  widths  shown,  planed,  tongued,  and  grooved.  The  side 
timbers  project  beyond  the  stanchions,  as  shown  in  views  (a)  and 
(c),  the  ends  being  let  into  same  and  further  secured  by  an  angle 
plate  4  inches  by  4  inches  (Fig.  21).  It  will  be  noticed,  by  reference 
to  Fig.  20  (c),  that  only  one  end  plate  is  shown.  This  is  on  account 
of  there  being  a  series  of  connected  boxes  in  a  line,  the  water  com- 
municating from  one  box  to  the  other.  The  partitions  of  the  boxes 


I 


t^i 


FIG.  21.     DOUBLE  DIESCHER  WASHER 

are  also  of  4-inch  timbers  reaching  down  to  the  angle  of  box  as 
shown  by  Fig.  20  (c).  Between  the  partitions  and  end,  it  will  be 
noticed,  there  is  a  space  8  inches  wide  right  under  the  stanchions 
(<;) ;  this  is  the  equilibrium  chamber,  and  is  provided  to  keep  the 
water  level  and  prevent  a  vacuum  being  formed.  Within  the 
partition,  there  is  a  lining  that  can  easily  be  renewed  and  serves  to 
confine  the  water  between  the  plunger  and  the  screen.  Above  the 
plunger,  an  angle-iron  frame  4  inches  by  4  inches  by  ^  inch  is  fixed 
as  shown  in  views  (c)  and  (d),  upon  which  the  wooden  frame  to 
which  the  screen  is  connected  rests;  this  angle  iron,  together  with 
the  screen,  is  not  fixed  perfectly  level,  but  is  inclined  1  inch  toward 
the  slate  valve  to  facilitate  the  discharge  of  the  coal  and  slate 
through  their  respective  openings. 


74 


TREATISE  ON  COKE 


The  plunger  is  of  cast  iron,  }-inch  metal,  5  feet  long  by  4  feet 
3  inches  wide,  with  four  buckled  surfaces,  as  shown  in  views  (a),  (c), 
and  (d),  in  the  center  of  each  of  which  is  a  small  hole  to  allow  the 
discharge  into  the  lower  chamber  of  any  fine  material  that  may  fall 
through  the  screen.  The  plungers  are  suspended  by  two  rods  of 
suitable  size,  as  shown  in  views  (a),  (c),  and  (d),  which  are  secured 
to  plunger  casting  by  means  of  collars  and  nuts,  the  casting  being 
specially  thickened  for  the  purpose,  view  (c).  The  suspension  rods 
connect  with  a  cross-bar,  as  shown  by  view  (c),  and  are  shielded 
from  the  coal  by  two  castings,  view  (d),  having  openings  4f  inches 
by  5  inches  by  7  inches  deep.  These  castings  are  connected  to  the 
washer  by  lagscrews.  The  plunger  has  a  stroke  according  to 
material  operated  upon,  ranging  from  1J  inches  to  2  inches,  the 

smaller  stroke  being 
most  suitable  for 
fine  material.  The 
3-inch  cross-shaft  is 
suspended  from  ec- 
centric or  main  dri- 
ving shaft  by  means 
of  two  cast-iron  ec- 
centric yokes,  as 
shown  by  views  (c) 
and  (d} ;  the  yokes 
are  steadied  by  a 
rod,  as  shown  in  (d). 
The  eccentric  or 
main  shaft  is  3J 
inches  in  diameter 
and  turns  in  bronze 
bearings,  resting  on 
the  girders  previ- 
ously referred  to ,  and 

is  generally  driven  by  a  32-inch  pulley,  making  70  to  80  revolutions 
per  minute,  according  to  the  stroke  of  plunger  and  the  material 
operated  upon.  Where  there  are  several  boxes,  the  plungers  rise 
and  fall  alternately,  thereby  balancing  each  other,  and  keeping 
the  water  beneath  them  in  equilibrium.  The  screens  of  the  boxes 
are  invariably  4  feet  square,  composed  of  a  rigid  wrought-iron  frame 
carrying  wires  of  spring  brass,  which  are  placed  parallel  in  the  direc- 
tion of  the  discharge,  having  a  space  between  of  about  -fa  inch. 
These  wires  are  fastened  to  the  frame  by  means  of  copper  wires  and 
all  the  joints  are  protected  by  solder.  It  will  readily  be  seen  that 
this  arrangement  secures  a  strong,  rigid,  and  durable  screen  that 
allows  free  passage  to  the  water  and  to  the  finest  pyrites  only.. 

The  slate  valve  is  fixed  in  the  position  shown  in  view  (d) ;  the 
body  of  the  valve  has  an  opening  on  both  sides,  6  inches  by  2  inches, 
the  area  of  which  can  be  modified  at  will  by  means  of  the  movable 


FIG.  22.     SINGLE  DIESCHER  WASHER 


TREATISE  ON  COKE  75 

valve  within,  which  is  operated  by  a  hand  wheel  and  screw.  The 
size  of  the  discharge  pipe,  view  (d),  varies  with  the  kind  of  material 
operated  upon.  At  the  bottom  of  washer,  a  casting  having  a 
valve  in  the  center  for  the  discharge  of  the  fine  pyrites  or  of  the 
water  when  necessary  is  secured  as  shown  in  views  (c)  and  (d). 
Access  is  provided  to  the  underside  of  the  plunger  by  means  of  a 
circular  manhole,  about  14  inches  in  diameter,  having  a  cast-iron 
arched  door  and  frame. 

The  correctness  of  the  principles  involved  in  the  construction  of 
the  Diescher  washer  is  noticeable  in  several  ways.  One  of  its  good 
points  is  that  the  position  of  the  plunger  is  directly  under  the  screen, 
which  produces  a  uniform  and  energetic  action  of  the  water  and  an 
equal  operation  all  over  the  screen  surface,  whereas,  when  the 
plunger  is  at  the  back,  an  unequal  action  of  the  water  is  produced 
on  the  screen,  the  effect  of  which  is  sometimes  only  partially 
obviated  in  other  machines  by  means  of  aprons  and  scrapers. 
Another  advantage  of  this  machine  is  that  the  water  enters  the 
upper  chamber  between  the  screen  and  the  plunger;  the  result  of 
this  is,  as  has  been  found  in  practice,  that  no  valves  are  necessary 
in  the  plunger,  although  these  are  put  in  when  especially  desired. 

The  washing  capacity  of  a  single  box  varies,  according  to  cir- 
cumstances, from  75  tons  of  coal  up  to  200  tons  in  10  hours,  accord- 
ing to  the  amount  of  dirt  and  pyrites  mixed  with  it.  The  cost  of 
washing  coal  with  the  Diescher  jig  varies  with  the  size  of  the  plant 
and  numerous  other  conditions.  One  man  can  attend  to  several 
boxes  as  easily  as  to  a  single-box  washer.  Even  in  the  most  unfavor- 
able circumstances,  the  cost  of  washing  the  coal  will  be  only  a 
small  fraction  of  1  cent,  per  bushel.  In  some  cases,  the  cost  is  less 
than  -TO  cent  per  bushel. 

The  Diescher  machines  have  been  in  practical  use  for  20  years, 
and  are  now  to  be  found  in  all  parts  of  the  United  States  and  even 
in  Mexico.  Their  reputation  for  simplicity,  durability,  great  capa- 
city, and  for  excellence  and  economy  of  the  washed  coal  makes 
them  very  popular  and  in  constantly  increasing  demand.  They  are 
manufactured  by  the  Scaife  Foundry  and  Machine  Company, 
Limited,  of  Pittsburg,  Pennsylvania. 


BROOKWOOD,  ALABAMA,  WASHERY 

The  coal-washing  plant  at  Brookwood,  Alabama,  Figs.  23  and 
24,  was  designed  by  Mr.  Walter  M.  Stein,  of  Philadelphia,  for  the 
Standard  Coal  Company.  The  following  description  is  by  Mr. 
Rudolph  Boericke,  superintendent,  and  was  written  in  response  to 
a  letter  of  inquiry  addressed  to  Mr.  Fred  M.  Jackson,  secretary 
and  treasurer  of  the  company: 

"The  coal  is  drawn  up  the  mine  slope,  by  wire-rope  haulage,  to 
the  top  of  a  wooden  trestle  50  feet  high,  where  it  is  dumped  into 


76 


TREATISE  ON  COKE  77 

a  storage  bin  c.  It  passes  first  over  a  double-table  shaking  screen  e, 
which  divides  it  into  three  sizes.  The  top  screen  is  of  1^-inch  mesh 
and  the  other  of  f-inch  mesh.  The  largest  size,  comprising  nut  and 
lump,  passes  over  two  picking  bands  /  and  g,  73  and  68  feet  long, 
respectively,  where  it  is  hand-picked  by  boys,  and  then  over  another 
single  shaking  screen  h,  of  3-inch  mesh,  which  takes  out  the  nut, 
which  falls  into  a  bin  x  and  is  carried  by  a  chute  to  the  cars. 
The  remaining  lump  is  delivered  to  the  lump  loader  i,  which  con- 
sists of  a  chain  of  buckets,  or  pans,  moving  on  iron  ways  and  in 
operation  is  exactly  the  reverse  of  an  elevator — instead  of  raising 
the  coal  it  lowers  it  into  the  car.  The  lower  end  swings  on  chains 
and  can  be  adjusted  to  any  height  of  car,  or  be  raised  clear  of  the 
train  while  the  cars  are  being  shifted. 

"To  return  to  the  coal  that  passes  through  the  first  or  1^-inch 
mesh  shaking  screen  e.  That  part  of  it  that  is  too  small  for  nut, 
yet  too  large  for  washing  purposes,  that  is,  that  which  passes  over 
the  f-inch  mesh,  falls  directly  to  the  crusher  /,  where  it  is  crushed 
and  returned  to  the  shaking  screen.  The  crushed  coal  and  all  the 
fine  coal  from  the  mine,  passing  through  the  f-inch  mesh  screen,  is 
sized  in  a  large,  double,  revolving  drum  /  into  three  sizes,  each 
size  being  washed  through  gutters  to  jigs  k  adapted  and  adjusted 
for  it.  There  are  eleven  double-compartment  plunger  jigs  in  all, 
each  capable  of  handling  from  5  to  7  tons  per  hour.  In  these  jigs, 
the  raw  coal  enters  at  one  end,  and  moves  across  both  compartments 
and  out  at  the  other  end  as  the  washed  product.  In  moving 
across,  the  slate,  pyrites,  barytes,  and  all  heavier  particles  find 
their  way  through  the  bed  to  the  bottom  of  the  jig  and  flow  out 
through  the  slate  valve  in  a  constant  stream.  The  washed  coal  is 
taken  to  the  boots  ov  o2  and  the  washed  slate  to  the  boot  q,  by 
means  of  gutters.  Perforated  bucket*  elevators  nlt  n2  moving 
slowly  to  drain  off  the  water,  raise  and  dump  the  washed  coal  into 
the  conveyer  p,  which  carries  it  to  the  storage  tower.  The  slate 
elevator  r  discharges  into  small  cars,  which  the  picking  boys  push 
to  the  slate  dump.  The  amount  of  water  used  in  this  plant  is  very 
small,  as  the  same  water  is  used  over  and  over.  By  allowing  it  to 
flow  through  a  settling  tank  u,  tolerably  clear  water  is  not  only 
obtained,  but  all  the  sludge  or  finer  particles  of  coal  that  are  held 
in  suspension  and  would  otherwise  be  lost  are  saved  and  elevated 
to  the  washed-coal  elevator  n±  by  the  perforated  bucket  elevator  w. 
The  water  from  the  settling  tank  flows  back  to  the  centrifugal 
pump  v,  which  again  forces  it  to  the  jigs,  etc." 

The  capacity  of  the  washer  is  500  tons  per  day  of  10  hours, 
though  owing  to  the-  limited  output  of  the  mines  at  present,  it 
has  not  been  handling  much  over  300  tons. 

The  table  of  analyses,  page  79,  shows  the  efficiency  of  the 
washer  very  plainly.  The  coke  is  hard  and  exceptionally  low  in  ash. 

To  obtain  the  average  for  a  day's  run  in  this  table,  samples  of 
run-of-mine  and  of  washed  coal  were  taken  every  half  hour: 


\ 


17303— in 


FIG.  25.     PLAN  OP  COAL- WASH 


J 

J 

J 

t 

y 

j 

r 

PLANT  AT  COAHUILA,  MEXICO 


ferr 


r.o3  no.  xo 


if  TJ 


• 


17303— in 


FIG.  25.     ELEVATION  OF  COAL-W 


Y 


S/cfe 


\TG  PLANT  AT  COAHUILA,  MEXICO 


TREATISE  ON  COKE 


79 


RESULTS  OF  WASHING  AT  BROOKWOOD,  ALABAMA 


Date 

Average  Per- 
centage of  Ash 
in  the  Run- 
of-Mine  Coal 

Average  Per- 
centage of  Ash 
in  the 
Washed  Coal 

Percentage 
Reduction  in 
Ash 

Average  Per- 
centage of  Ash 
in  the  Coke 

December  21  

15.32 

8.15 

46.9 

10.10 

December  23  

14.10 

7.50 

46.9 

9.50 

December  31 

15.07 

6.50 

56.8 

1  anuary  5  
anuary  6 

20.83 

17.18 

8.10 
7.60 

61.3 
55.5 

10.50 
10.50 

anuary  7              .  . 

16.38 

6.50 

60.2 

9.27 

anuary  26  
anuary  27  
January  28  

20.90 
17.37 
18.63 

5.50 
5.40 
7.15 

73.5 
69.0 
61.7 

February  13  
February  14  
February  17  

21.12 

4.81 

77.5 

6.10 

7.40 
7.80 

The  run-of-mine  that  is  washed  is  a  mixture  of  the  No.  4  and 
No.  6  seams;  that  from  No.  4  is  finely  interstratified  with  slate  and 
contains  an  abundance  of  sulphur.  There  is  a  lack  in  sulphur 
determinations,  but  a  casual  examination  of  the  washed  slate  and 
of  the  washed  coal  shows  that  it  is  removed  almost  entirely.  The 
washer  is  the  first  of  its  kind  in  the  United  States,  though  not  in 
America,  as  there  is  a  300-ton  plant  in  successful  operation  at 
Ferrona,  Pictou  County,  Nova  Scotia;  the  New  Glasgow  Iron, 
Coal,  and  Railway  Company  operate  it  in  connection  with  their 
blast  furnace. 

Mr.  Stein  writes  that  an  addition  will  be  made  to  the  plant  in 
the  shape  of  a  large  elevator  with  automatic  dumper  for  feeding 
coal  from  a  storage  bin;  this  will  hold  250  tons  of  coal,  and  will 
enable  the  company  to  operate  the  washer  to  its  fullest  capacity 
during  the  day.  Another  perforated  bucket  elevator  will  also  be 
added  for  removing  the  dust  from  the  settling  tank. 

The  sulphur  has  been  reduced  to  .52,  .54,  and  .53  per  cent, 
from  1.65  per  cent,  of  sulphur  in  the  coal  of  one  of  the  seams  used 
in  making  coke,  and  1.15  per  cent,  of  sulphur  in  the  coal  of  the 
other  seam.  This  shows  good  work,  with  a  very  small  loss  of 
fine  coal. 


COAL-WASHING    PLANT    FOR    BITUMINOUS    COALS    AT 
COAHUILA,  MEXICO 

I  am  indebted  to  Mr.  Edgar  G.  Tuttle,  E.  M.,  for  the  following 
account  of  the  Coahuila  plant,  which  was  first  published  in  the 
School  of  Mines  Quarterly,  No.  4,  Vol.  XVII. 

Fig.  25  (a)  and  (b)  shows  a  coal-washing  plant  arranged  for 
treating  about  300  tons  a  day  of  10  hours;  the  design  embodies 
almost  all  of  the  requirements  likely  to  be  met  with  in  coal  washing. 


80  TREATISE  ON  COKE 

The  extent  of  sizing  by  screens  and  the  washing  are  designed  to 
treat  a  coal  whose  impurities  separate  with  more  difficulty  than 
in  the  case  of  impurities  as  heavy  as  iron  pyrites  or  heavy  slates. 
For  a  simpler  treatment,  the  plant  can  be  considerably  modified. 
The  relative  positions  of  the  machines  may  require  to  be  differently 
arranged  under  various  circumstances  connected  with  the  location, 
and  depending  on  the  respective  distances  and  directions  at  which 
the  coal  arrives  at  the  plant  and  the  point  at  which  it  is  discharged. 
The  main  features  of  the  plant  can,  however,  be  carried  out  to 
suit  the  above  by  making  as  many  right  breaks  in  the  lines  of 
machinery  as  may  be  necessary  to  bring  the  plant  in  the  desired 
position  and  connect  the  points  of  receiving  and  delivery  with  its 
entering  and  terminating  points.  If,  then,  the  position  of  any 
machine  is  such  as  not  to  permit  of  being  driven  by  the  main-line 
shafting,  right-angle  gears  can  be  introduced  to  transmit  power 
thereto. 

In  this  plant,  the  screening  is  designed  to  be  done  wet;  where 
the  screening  is  done  dry,  greater  fall  throughout  the  line  is  neces- 
sary. Generally,  where  screening  is  done  in  the  dry  way,  it  is 
accomplished  in  one  large  revolving  screen  or  a  drum  screen  consist- 
ing of  two  or  three  concentric  screens  inside  one  another,  each  of  a 
different  mesh  of  perforated  metal  or  wire  cloth.  Sometimes  a 
shaking  screen  with  several  parallel  screening  surfaces,  one  above 
the  other  and  each  of  different  mesh,  is  used  to  produce  as  many 
sizes  as  desired.  Where  the  screening  is  done  dry,  the  jigs  should 
be  located  more  directly  below  the  screen,  or  that  part  of  the  screen 
from  which  they  receive  the  sized  product. 

The  treatment' of  the  coal  in  this  plant  is  as  follows:  The  coal 
received  is  that  which  usually  passes  through  the  screens  in  the 
chute  at  the  mine  tipple.  This  may  be  what  falls  through  flat-bar 
screens  spaced  about  1^  inches  apart,  or  through  revolving  or  sha- 
king screens  of  somewhat  larger  mesh.  It  is  assumed  that  the  coal 
sent  to  the  washer  will  not  be  much  larger  than  3  inches  at  its 
greatest  dimension,  as  all  above  this  will  be  better  hand-picked  at 
the  tipple  and  is  not  readily  handled  in  the  size  of  elevator  buckets 
that  are  of  sufficient  capacity  for  the  greater  proportion  of  the 
sizes  requiring  treatment.  The  coal  less  than  3  inches  in  size  is 
then  either  dumped  into  the  pit  a  from  the  chute  of  the  mine  tipple, 
if  it  is  located  near  enough  to  the  washer  plant,  or  it  is  unloaded 
into  the  pit  from  railroad  cars.  From  here,  the  coal  is  lifted  by 
the  elevator  b  to  the  shaking  screen  c,  which  has  an  upper  sheet 
steel  screen  with  1^-inch  circular  perforations  and  an  under  one  of 
j-inch  perforations.  The  coal  is  here  separated  into  the  following 
sizes  and  disposed  of  as  indicated:  All  greater  than  1£  inches 
passes  over  the  screen  and  is  delivered  on  the  picking  belt  d.  Coal 
passing  through  the  1^-inch  screen  and  over  the  f-inch  screen  (size 
}  inch  to  1^  inches)  falls  between  the  coarse  rolls  e,  which  reduce 
the  coal  to  inch  or  less. 


TREATISE  ON  COKE  81 

The  coal  passing  through  the  f -inch  perforations  of  the  shaking 
screen  (size  0  inch  to  f  inch)  falls  to  the  foot  of  the  elevator  /.  This 
coal,  with  that  from  the  rolls  reduced  to  f  inch  or  less,  is  lifted  by 
the  elevator  /  to  the  revolving  screen  g  at  the  head  of  a  line  of  three 
screens,  which  are  each  4  feet  in  diameter  and  about  11  feet  long, 
and  of  the  same  construction  except  that  they  are  covered  with 
screens  of  different  mesh.  The  screen  g  is  divided  into  four  sections 
in  the  direction  of  its  length  and  each  section  is  the  same  width; 
the  first  two  are  covered  with  sheet  iron  or  steel  with  ^-inch  circular 
perforations  and  the  last  two  with  screens  of  f-inch  perforations. 

The  coal  passing  through  the  |-inch  screen  openings  (size  0  inch 
to  \  inch)  falls  to  aprons  below,  which  are  on  each  side  of  the  screen 
and  slope  into  an  inclined  gutter  directly  below  the  screen,  which 
leads  this  material  (0  inch  to  \  inch)  into  the  screen  h,  with  the 
water,  which  falls  from  a  spray  pipe  over  the  length  at  the  top  of 
the  screen  to  wash  out  particles  becoming  wedged  in  the  holes  and 
clear  the  coal  from  sticking  to  the  sides  of  the  screen.  The  water 
is  sprayed  similarly  on  all  the  screens,  and  falling  through  into 
the  gutter,  carries  the  coal  passing  through  the  perforations  of  one 
screen  into  the  next  screen. 

The  coal  passing  through  the  J-inch  perforations  (size  J  inch  to 
J  inch)  is  -spouted  to  the  jigs  i,  j,  k,  and  /,  which  are  designed  for 
treating  coarse  sizes  and  are  provided  with  crank-arm  or  slide-yoke 
motion,  so  as  to  have  a  quick  down  stroke  of  the  plunger  and  a 
slow  return  movement,  and  speeded  to  make  about  60  strokes  a 
minute  of  3-inch  to  4-inch  throw,  and  if  a  middle  product  is  to  be 
treated  the  screens  are  arranged  for  drawing  this  off  for  retreatment. 

If  there  has  been  any  of  the  }-inch  to  1^-inch  coal  from  the 
shaking  screen  that  has  not  been  reduced  to  less  than  f  inch  by 
the  rolls,  after  this  has  been  elevated  and  passed  into  the  screen  g, 
it  will  go  over  it  and  out  at  the  end,  and  will  be  again  fed  to  the 
rolls  e  for  reduction,  and  will  be  then  hoisted  by  the  elevator  / 
with  the  coal  from  the  shaking  screen,  as  already  described.  If  the 
rolls  e  do  not  reduce  this  amount  of  coal  sufficiently,  it  can  be 
passed  to  the  rolls  b'  for  smaller  crushing  and  treatment  with  other 
coal  passing  through  these  rolls. 

If,  however,  the  coal  passing  out  of  the  screen  g  is  not  too  large 
for  washing  and  the  impurities  are  sufficiently  unlocked  without 
further  reduction,  it  may  be  cleaned  completely  by  washing  on 
jigs  treating  coarse  sizes,  or  it  may  be  sufficiently  cleaned  to  be 
used  for  certain  purposes  that  do  not  warrant  its  reduction  to 
smaller  sizes  for  what  further  improvement  may  be  thus  made 
possible.  In  this  case  the  coal,  as  it  passes  out  of  the  screen  g,  can 
be  spouted  to  one  or  two  of  the  first  jigs  treating  coarse  sizes,  using 
for  this  purpose,  say,  jigs  j  and  k  (that  is,  for  coal  larger  than 
}  inch),  and  jigs  i  and  /  for  the  sizes  \  inch  to  J  inch,  or  such  pro- 
portion of  these  or  other  jigs  as  may  be  necessary  for  the  quantity 
of  these  sizes  produced. 


82  TREATISE  ON  COKE 

Although  a  preliminary  examination  and  test  of  the  coal  will 
determine  the  quantity  of  each  size  of  the  larger  sizes  of  coal,  and 
the  number  of  jigs  required  to  treat  it,  it  is  advisable,  in  designing 
the  jigs  and  arranging  them  in  the  plant,  to  provide  for  possibilities 
of  treating  larger  sizes  on  some  of  the  jigs  intended  to  treat  smaller 
sizes,  or  the  reverse.  The  points  to  be  considered  in  this  connec- 
tion are:  (1)  Designing  jigs  so  that  the  length  of  the  stroke  and 
the  number  per  minute  can  be  readily  increased  or  diminished  to 
suit  the  sizes  treated.  (2)  Locating  the  jigs  under  the  screens  so 
that  the  material  likely  to  be  received  from  one  or  more  points  of 
the  same  can  be  readily  spouted  to  the  jigs  with  changes  in  sizes 
to  be  treated  thereon.  (3)  Arranging  the  jigs  so  that  the  washed 
product  and  the  refuse  discharged  therefrom  can  be  readily  deliv- 
ered to  the  points  desired,  which  may  vary  with  the  sizes  produced 
on  account  of  possible  difference  in  the  quality  of  different  sizes. 
(4)  In  case  a  middle  product  results  requiring  treatment,  the  jigs 
should  be  arranged  and  handily  located  so  that  these  can  be  drawn 
off  and  discharged  to  rolls  for  reduction,  or  else  be  handy  to  an 
elevator  to  lift  this  product  to  rolls  intended  for  this  purpose  or 
for  smaller  crushing. 

The  0-inch  to  ^-inch  coal  carried  into  screen  h  is  separated  into 
sizes  as  follows :  Size  0  inch  to  J  inch  is  screened  through  the  first 
two  sections  with  J-inch  holes,  and  is  caught  by  the  aprons  and 
gutter  below  the  screen  and  spouted  into  the  screen  m.  The  coal 
passing  over  the  first  two  sections  of  screen  h  will  be  J  inch  to  ^  inch 
in  size.  This  passes  into  the  last  two  sections  of  screen  h  with 
f-inch  perforations,  which  separate  it  into  two  sizes,  as  follows: 
First,  coal  passing  through  the  f-inch  holes  (J  inch  to  f  inch), 
which  is  spouted  to  jigs  n  and  o\  second,  coal  passing  over  and 
out  of  the  end  of  this  screen  (f  inch  to  £  inch),  which  is  spouted 
to  jigs,  p,  q,  r,  and  s. 

The  coal  spouted  from  the  gutter  under  the  screen  h  into  screen 
m  (0  inch  to  i  inch)  is  separated  as  follows:  The  coal  passing 
through  the  first  two  sections  of  this  screen  with  -r6--inch  holes 
(size  0  inch  to  iV  inch),  falls  into  the  gutter  below  it,  and  if  suffi- 
ciently pure,  need  not  be  treated,  but  can  be  spouted  directly  into 
the  sluice  boxes  carrying  washed  coal  from  the  jigs.  If,  however, 
it  contains  impurities  and  there  is  a  considerable  quantity  of  this 
size,  it  will  require  treatment.  Generally,  it  will  suffice  to  spout 
this  coal  into  the  jigs  /  and  u  arranged  for  treating  this  size  and  in 
the  jigging  thereof  most  of  the  overflow  will  be  pure  coal  with 
possibly  some  light  mud,  which  will  subsequently  pass  off  in  the 
water  overflowing  from  the  settling  tank  where  the  fine  coal  will 
be  treated  for  its  deposition  from  suspension  in  the  water  from 
the  jigs.  If,  however,  the  impurities  separate  with  difficulty,  this 
material  0  inch  to  Tg-  inch  will  be  carried  along  in  the  gutter  under 
the  screen  m  to  the  hydraulic  classifier  v  for  treatment,  as  will 
be  described. 


TREATISE  ON  COKE  83 

The  coal,  -r6-  inch  to  J  inch,  passing  into  the  last  two  sections 
of  the  screen  m  with  J-inch  holes,  is  separated  as  follows:  That 
passing  through  the  screen  sections  (iV  inch  to  J-  inch)  is  spouted 
to  jigs  w  and  x.  The  coal  passing  out  of  the  end  of  this  screen  is 
sized  J  inch  to  J  inch,  and  is  spouted  to  jigs  y  and  z. 

The  coal  is  spouted  from  screens  to  the  jigs  through  troughs 
6  inches  square  or  so  inside,  lined  with  No.  12  or  14  sheet  iron. 
Sometimes  storage  boxes  are  introduced  below  the  screens  to  hold 
the  sized  screenings,  and  from  these  it  is  spouted  to  the  jigs.  They 
are,  however,  apt  to  clog  up  with  wet  screenings.  A  more  satis- 
factory means  of  insuring  a  steady  supply  to  the  jigs  is  to  arrange 
a  regular  feed  to  the  elevator  b,  and  to  keep  a  sufficient  supply  of 
raw  coal  always  on  hand  in  the  pit  a. 

The  jigs  i,  j,  k,  and  /  are  of  one  compartment  about  3  feet  square, 
and,  as  mentioned,  are  arranged  to  draw  off  a  middle  product,  that 
is,  material  on  the  jig  bed  from  a  horizon  between  the  top  layer 
of  washed  coal  and  the  bottom  layers  of  slate.  Impurities  in  the 
form  of  small  particles  closely  adhering  to  the  coal  are  most  apt  to 
occur  among  the  larger  sizes  of  coal;  or,  if  consisting  of  particles 
of  coal  of  an  inferior  quality,  or  of  bony  coal,  intermediate  in  specific 
gravity  between  the  lighter  coal  at  the  top  of  the  bed  and  the  slate 
or  impurities  on  the  bottom  of  the  jig  bed,  they  will  occur  in  a 
layer  midway  between  the  two,  whence  they  may  be  drawn  off  in 
jigs  arranged  for  the  purpose.  The  remaining  jigs  are  of  two  com- 
partments, each  compartment  being  24  inches  by  32  inches.  These 
jigs  are  speeded  at  100  to  180  revolutions,  or  double  strokes,  per 
minute,  and  with  throws  of  2£  inches  for  the  larger  sizes  to  J  inch 
for  the  smallest  sizes.  If  the  impurities  are  with  difficulty  sepa- 
rated from  the  coal  in  the  smaller  sizes,  it  may  be  necessary  to 
have  three  compartments  instead  of  two  in  the  jigs  w,  t,  u,  and  x, 
so  that  the  material  will  travel  over  a  greater  length  of  jig  bed  in 
being  treated,  thus  allowing  more  time  to  effect  the  separation. 

The  coal  after  being  washed  passes  out  of  the  jigs  at  the  over- 
flow into  the  trough  a,  and  is  carried  by  the  water  from  the  jigs 
to  the  drainage  screen  cr ,  which  is  preferably  covered  with  sheet 
copper  of  gV- inch  perforations,  where  the  water  is  removed  and  all 
coal  larger  than  -2-5-  inch  passes  over  the  screen  and  out  at  the  end 
to  the  elevator  d',  whence  it  is  raised  high  enough  for  discharging 
either  into  bins  or  else  to  a  point  for  loading. 

Jigs  may  be  used  from  which  the  water  does  not  flow,  and 
from  which  the  coal  is  removed  by  elevators  with  perforated 
buckets,  or  if  the  coal  overflows  with  water  from  the  jigs,  the 
water  may  be  drained  therefrom  by  passing  over  screens  forming 
the  overflow  chute.  In  this  case,  there  must  be  sufficient  fall  to 
cause  flow  if  the  coal  is  to  be  chuted  dry  from  the  jigs  to  the  eleva- 
tor d',  or  the  jigs  may  have  less  inclination  or  be  located  on  the 
same  level,  provided  that  conveyers  are  introduced  to  convey  all 
the  coal  from  the  jigs  to  the  foot  of  the  elevator  d' . 
4 


84  TREATISE  ON  COKE 

Where  coal  is  to  be  stored  in  bins  of  considerable  extent  a  cori- 
veyer  e' ,  into  which  the  coal  from  the  elevator  is  delivered,  is 
arranged  at  the  top  of  the  bins.  The  conveyer  travels  the  length 
of  the  bins  near  their  center  lines,  and  is  so  designed  that  by  means 
of  openings  in  the  bottom  of  the  conveyer  box,  that  can  be  opened 
or  closed  as  desired,  the  discharge  of  the  coal  into  the  bin  from  any 
point  thereof  is  effected,  permitting  of  an  even  distribution  of 
coal  in  the  bin.  The  buckets  of  the  elevator  d'  are  perforated  so 
as  to  drain  as  much  of  the  water  from  the  coal  as  possible.  The 
water  and  coal  less  than  -£$  inch  in  size,  passing  through  the  drain- 
age screen  cf ,  fall  upon  an  apron  and  into  the  gutter,  from  which 
they  flow  by  the  trough  /'  to  the  settling  tank  gr .  The  trough  ef 
leads  to  one  side  of  the  settling  tank,  and,  by  means  of  small  adjust- 
able openings  along  the  side  of  this  trough,  the  discharge  of  the 
water  with  the  fine  particles  of  coal  into  the  settling  tank  can  be 
regulated  so  as  to  be  evenly  distributed,  which  is  important  to 
secure  effective  settling.  The  water  and  fine  coal  are  discharged 
into  the  settling  tank  on  one  side  of  a  partition  h'  that  extends 
the  length  of  the  tank  with  its  bottom  3  or  4  inches  below  the 
surface  of  the  water;  this  causes  the  water  flowing  into  the  tank 
to  move  first  in  a  downward  current,  and  then  across  the  tank,  as 
an  even,  slowly  moving  body  of  water,  toward  the  discharge  side. 
Surface  currents  are  thus  prevented,  which  would  otherwise  occur 
and  carry  the  material  over  the  surfaces  and  out  at  the  discharge 
without  settling. 

The  settling  tank  is  12  feet  wide,  32  feet  long,  and  4  or  5  feet 
deep  at  center,  with  sides  sufficiently  inclined  that  particles  will 
not  settle  thereon. 

The  suspended  coal  of  sand  and  slime  sizes  is  thus  settled,  and, 
by  means  of  a  slowly  moving  drag  i'  with  pedals  or  scrapers  4  feet 
apart,  the  settlings  are  moved  gently  along  and  finally  scraped 
up  an  incline  and  out  of  the  tank  and  dropped  off  at  the  end  of  the 
drag,  which  delivers  the  settlings  at  a  point  where  they  will  fall  and 
mix  with  the  coal  from  the  discharge  end  of  the  drainage  screen  c' 
and  both  be  taken  up  by  the  elevator  d' . 

The  water  overflowing  from  the  settling  tank  with  what  sus- 
pended matter  it  may  still  contain,  which  will  be  very  small,  over- 
flows into  the  trough  /'.  It  is  important  that  this  overflow  be 
truly  level  so  that  the  water  from  the  settling  tank  will  overflow 
in  an  even  sheet,  thus  insuring  a  slowly  moving  current  through 
the  settling  tank.  From  the  overflow  trough  /'  the  water  flows 
into  the  trough  k'  to  the  sump  /',  from  which  it  is  lifted  by  the 
centrifugal  pump  mf  and  delivered  through  pipes  or  launder  boxes 
to  screens  and  jigs  treating  the  smaller  sizes.  Any  overflow  water 
from  this  sump  passes  to  the  sump  ri . 

The  refuse,  impurities,  slate,  etc.  drawn  off  from  the  jigs,  as 
well  as  the  material  settling  through  the  sieves  of  the  jig  bed  and 
released  at  the  bottom  or  mud-discharge,  are  conveyed  with  the 


TREATISE  ON  COKE  85 

water  escaping  therefrom  by  the  slate  troughs  to  the  pit  tf .  These 
troughs  are.  more  highly  inclined  for  the  large-sized  slates  to  facili- 
tate their  movement  to  the  pit  </.  The  slate  troughs  are  best 
located  on  the  floor  near  the  base  of  the  jigs  or  else  below  the  floor 
line,  with  the  flooring  from  all  the  jigs  sloping  thereto  so  as  to 
drain  off  all  water  escaping  or  leaking  from  jigs,  pipes,  troughs,  etc., 
and  keep  the  floors  clean.  The  slate  troughs  are  usually  made 
4  inches  to  6  inches  square,  lined  with  No.  12  or  14  sheet  iron, 
curved  at  the  bottom.  The  amount  of  water  escaping  with  the 
refuse  is  comparatively  small  in  comparsion  to  that  flowing  with 
the  washed  coal  from  the  jigs.  The  pit  or  need,  therefore,  not  be 
very  large.  The  one  here  shown  is  8  feet  square  at  top,  with  sides 
sloping  about  50  degrees,  and  3  to  3^  feet  deep. 

The  refuse  is  removed  from  the  pit  o'  by  the  elevator  pf  with 
perforated  buckets  to  drain  off  the  water  taken  up  by  them  with 
the  material.  The  refuse  is  discharged  at  the  elevator  head  into  the 
storage  bin  q'  for  removal  by  railroad  or  dump  cars  or  otherwise. 

If  the  location  of  the  plant  is  on  an  elevation  where  there  is 
considerable  low  land  that  can  be  filled,  the  refuse,  escaping  with 
water  from  the  jigs  treating  the  smaller  sizes,  can  be  carried  in 
troughs  with  a  grade  of  4-  or  1  foot  fall  per  100  feet  to  such  points 
where  the  refuse  can  be  disposed  of  to  make  fills.  If  there  is 
sufficient  fall,  the  refuse  from  the  jigs  treating  coarser  material  can 
be  likewise  disposed  of  in  troughs  of  steeper  grade,  viz.,  2  per  cent, 
to  4  per  cent.  fall.  If  there  is  only  sufficient  fall  for  disposing  of 
the  smaller-sized  refuse  as  above,  the  heavier  or  larger-sized  refuse 
may  have  to  be  removed  by  the  elevator  p'  and  disposed  of  as 
indicated. 

The  water,  after  the  refuse  has  been  settled  therefrom  into  the 
pit  or ,  overflows  into  the  trough  r'  and  flows  to  the  sump  n',  from 
which  it  is  lifted  by  the  centrifugal  pump  s'  and  is  delivered 
through  pipes  or  water  troughs  to  the  jigs  treating  the  coarse 
sizes  and  the  rolls. 

The  middle  product  drawn  off  of  jigs  i,  /,  k,  and  /  is  spouted  to 
the  roll  bf  and  reduced  from  J  inch  or  f  inch  to  about  f  inch 
downwards,  depending  on  how  small  it  is  found  necessary  to  reduce 
the  middle  product  to  unlock  the  impurities.  This  material  is 
then  lifted  by  the  elevator  f  high  enough  to  be  discharged  into  the 
revolving  screen  h  and  there  treated  with  the  sizes  of  coal  dis- 
charged into  this  screen  from  the  screen  g ;  this  is  the  case  if  the 
middle  product  has  been  reduced  to  sizes  small  enough  to  be  sized 
in  the  screen  h.  If  it  is  not  necessary  to  reduce  all  the  middle 
products  to  sizes  smaller  than  those  treated  in  screen  g,  it  is  lifted 
by  the  elevator  f  only  high  enough  to  be  discharged  into  the  ele- 
vator /,  and  from  there  it  is  handled  the  same  as  the  other  coal 
lifted  by  this  elevator. 

The  coal  that  passes  over  the  l^-inch  perforations  of  the  shaking 
screen  c,  which  will  be  from  1 J  inches  to  3  inches  or  so  in  size,  is 


86  TREATISE  ON  COKE 

delivered  on  to  the  traveling  picking  band  or  belt  d,  where  it  is 
hand-picked  by  as  many  men  or  boys  located  along  both  sides  of 
the  belt  as  may  be  required  to  thoroughly  clean  the  coal  as  it  is 
conveyed  toward  the  storage  bin  u' ,  where  it  is  dumped  for  loading 
on  railroad  cars.  This  belt  is  3  or  4  feet  wide  and  about  40  feet 
long,  and  has  a  slow  travel  of  about  30  feet  a  minute.  It  is  com- 
posed of  sections  of  wood  or  iron  3  inches  to  6  inches  wide  by 
3  feet  or  4  feet  long,  whose  ends  are  fastened  to  sprocket,  or  link, 
chains.  The  sections  of  wood  or  iron  are  either  beveled,  jointed, 
grooved,  or  hinged,  so  as  to  lay  close  to  each  other  and  form  a 
flexible  band  readily  curving  around  the  sprocket  wheels  of  the 
driving  gear.  If  these  sections  are  of  iron  they  generally  lap 
each  other  where  their  sides  come  in  contact  and  form  a  sort  of 
hinge  joint. 

If  the  coal  treated  on  the  picking  band  is  of  large  sizes  requiring 
sledging  and  slabbing,  so  that  it  is  broken  up  in  cleaning  and  con- 
siderable small  coal  results,  the  sections  or  slats  of  the  picking 
band  are  sometimes  slightly  separated  from  each  other  so  as  to 
act  somewhat  like  a  screen  and  allow  the  small  coal  produced  to 
fall  through  and  thus  separate  it  from  the  large  lumps  in  loading. 
The  impurities  picked  from  the  coal  traveling  on  the  band,  which 
may  contain  more  or  less  coal,  are  dropped  into  chutes  leading  to 
the  pit  v'  or  else  are  thrown  into  this  pit,  and  from  there  are  lifted 
by  the  elevator  «/  back  to  the  washer  building  and  high  enough  to 
be  discharged  on  the  rolls  e  for  reduction  and  delivery  to  the  ele- 
vator /  for  the  usual  treatment  in  the  plant. 

If  there  is  much  refuse  picked  from  the  lump  coal  at  the  mine 
tipple  and  it  has  considerable  good  coal  adhering  to  it,  it  can  be 
broken  by  sledging,  or  a  special  crusher  may  be  erected  for  redu- 
cing it,  after  which  it  is  discharged  into  the  pit  v'  and  lifted  by  its 
elevator  for  treatment  in  the  plant  with  other  coal  from  the  pit. 
If  this  waste  removed  at  the  mine  tipple  is  not  too  large  and  the 
tipple  is  near  the  washer  plant,  it  may  be  chuted  directly  to  the 
rolls  e.  If  the  tipple  is  located  at  some  distance  and  this  refuse  is 
to  be  treated,  it  will  be  necessary  to  take  it  there  by  railroad  cars, 
dump  cars,  or  a  conveyer,  if  the  distance  is  not  too  great.  If  the 
amount  of  coal  requiring  hand  picking  is  large,  it  may  be  necessary 
to  introduce  two  picking  belts.  This  is  generally  preferable  to 
increasing  the  length  of  the  belt  with  increased  quantity  to  be 
treated.  The  maximum  length  for  a  picking  belt  should  be  30 
to  50  feet. 

If  the  impurities  in  the  sizes  f  inch  to  1|  inches,  separated  on 
the  shaking  screen,  do  not  adhere  to  the  coal  and  are  readily  hand- 
picked,  they  need  not  be  reduced  in  the  rolls,  as  mentioned,  but 
can  be  discharged  into  a  second  picking  belt  that  may  be  intro- 
duced for  treating  these  sizes  as  explained  for  the  1^-inch  to  3-inch 
sizes.  They  may  be  delivered  into  bins,  if  they  are  to  be  loaded 
for  shipment,  or  the  picking  belt  on  which  they  are  treated  may 


TREATISE  ON  COKE  87 

have  such  a  direction  of  travel  as  to  finally  discharge  them  at  the 
foot  of  elevator  df  for  removal  with  the  other  coal  hoisted  by  this 
elevator.  Or,  if  the  impurities  are  in  considerable  quantity  in 
the  f-inch  to  IJ-inch  sizes,  they  may  be  removed  by  washing,  if 
they  do  not  adhere  to  the  coal,  so  as  to  require  crushing  to  liberate 
them.  This  size  may  then  be  dropped  from  the  shaking  screen 
with  the  0-inch  to  f-inch  size  and  hoisted  with  it  by  the  elevator  / 
to  the  screen  g  without  first  passing  through  the  rolls  e.  In  this 
case,  this  sized  coal  will,  as  previously  explained,  pass  over  the 
screen  g  and  out  at  the  end,  sized  }  inch  to  1^  inches,  and  fall  into 
the  two  jigs  j  and  k,  or  others  that  may  be  required  for  treating  it. 

The  hydraulic  classifier  v  consists  of  a  box  of  two  or  more 
compartments,  2  feet  or  more  in  width,  and  of  such  length 
as  is  determined  by  the  number  of  classes  of  sizes  it  is  intended 
to  produce.  The  sides  are  sloping  to  insure  proper  discharge  of 
the  materials  settled  therein  from  the  bottom,  which  is  fitted  some- 
times with  piping,  as  will  be  described.  A  partition  extending 
2  inches  or  4  inches  into  the  water  of  the  classifier  extends  across 
its  width  so  as  tb  deflect  the  inflow  of  water  and  direct  its  current 
downwards,  thus  preventing  surface  currents. 

The  treatment  of  0-inch  to  -iV-inch  size  flowing  from  the  gutter 
under  screen  m  to  the  classifier  is  as  follows:  With  the  diminution 
of  the  velocity  of  the  current  of  water  flowing  from  the  narrow 
channel  of  the  gutter  into  the  wider  channel  of  the  classifier,  there 
will  be  deposited  in  the  first  compartment  %'  of  the  apparatus, 
such  smaller  sizes  of  the  heavy  impurities  and  such  larger  sizes  of 
the  lighter  coal  as  are  equally  settling.  Likewise  in  the  second 
compartment  y,  there  will  be  a  settling  of  relatively  smaller  sizes. 
It  will  depend  considerably  on  the  nature  of  the  impurities  and 
coal  in  these  smaller  sizes  as  to  what  the  treatment  will  be. 

The  ideal  method  of  treating  material  classified  as  above  is  to 
submit  it  to  treatment  with  water  on  machines  of  the  type  of  the 
inclined  table,  or  shaking  or  bumping  tables,  where  the  larger, 
specifically  lighter  particles  of  coal  will  be  moved  farther  down  the 
plane  by  the  water  than  the  smaller,  specifically  heavier  particles 
of  slate  or  impurities.  In  coal  washing,  however,  the  cost  of  this 
treatment  is  too  great  and  the  small-sized  material  is  usually  in 
too  small  a  quantity  and  of  insufficient  value  to  warrant  the 
expense  of  the  treatment,  or  the  coal  may  be  sufficiently  rich  not  to 
require  treatment. 

The  trough  washer  is  a  machine  nearest  approaching  the  types 
above  mentioned  that  it  is  advisable  to  incur  the  expense  of, 
although  the  treatment  of  the  coal  therein  is  not  perfect.  This  is 
used  for  sizes  up  to  1£  inches  or  so  in  rough  washing,  but  is  better 
adapted  for  the  smaller  sands  and  slime  sizes  or  the  products  of 
the  hydraulic  classifier  in  question. 

The  trough  washer  consists  of  a  trough  inclined  1  foot  in  12, 
from  40  to  60  feet  long  and  1  or  2  feet  wide  at  bottom ;  sides  sloping 


88  TREATISE  ON  COKE 

from  50°  to  60°.  In  this,  a  scraper  chain  works,  with  a  scraper 
4  inches  to  6  inches  deep  and  6  feet  apart,  closely  fitting  the  bottom 
of  the  trough  and  moving  slowly  up  the  incline.  The  fine  coal  is 
fed  into  the  trough  midway  between  the  two  ends  and  60  to  150 
gallons  of  water  a  minute  are  fed  into  the  trough  at  the  upper  end. 
The  action  of  the  water  is  to  wash  the  coal  down  the  trough  and 
over  the  tops  of  the  scrapers,  while  the  heavier  impurities  settle  to 
the  bottom  and  are  moved  up  the  trough  by  the  scrapers  and 
discharged  over  the  top.  The  coal  discharged  at  the  lower  end  of 
the  trough  with  the  water  is  drained  over  a  screen  and  the  water 
thus  separated  and  reused,  but  preferably  it  can  be  discharged 
into  the  settling  tank  /'  and  there  removed  by  the  drag  where 
this  fine  coal  can  be  handled  and  used  better  when  mixed  with 
coarser  coal. 

Generally,  however,  a  separation  of  the  impurities  from  the 
classified  products  of  the  two  compartments  of  the  hydraulic  classi- 
fier that  will  be  sufficiently  satisfactory  where  the  quantities  are 
small  can  be  effected  by  allowing  the  settlings  from  the  compart- 
ment yf  to  pass  out  of  the  spigot  zf  to  the  jig  x,  and  those  from  y 
flowing  from  the  spigot  a"  to  pass  to  the  jig  u,  where,  in  rapid  jig- 
ging, somewhat  of  a  separation  is  effected  if  the  strokes  of  the  jig 
last  only  during  the  period  of  accelerated  velocity  of  fall  of  the 
particles.  In  this  case,  the  larger  lighter-weight  particles  of  coal 
require  a  longer  time  before  arriving  at  their  maximum  velocity 
of  uniform  motion  than  the  smaller  heavier  particles  of  impurities. 
With  strokes  of  the  jig  applied  to  last  for  -§-  or  iV  second  or  so, 
particles  of  coal  and  slate  that  are  equally  settling  in  the  classifier 
may  be  separated  to  some  extent  on  the  jigs,  the  coal  being  main- 
tained at  the  top  of  the  bed  and  the  slate  settling  to  the  bottom 
as  usual. 

If  there  is  only  a  slight  difference  between  the  specific  gravity 
of  the  coal  and  slate,  it  may  be  advisable  to  make  the  smallest  size 
treated  on  the  jigs  from  the  screens  -2-B-  inch  or  gV  inch ;  in  this  case, 
the  TV-inch  screen  should  be  replaced  by  a  gV-inch  or  -3-2-inch  copper 
screen  of  perforated  metal  or  wire  cloth.  In  this  case,  the  largest 
size  treated  by  the  classifier  will  be  -^V  inch  or  -£$  inch.  The  use 
of  small  screens  should  be  avoided,  however,  if  possible,  as  their 
life  is  short  and  the  value  of  the  material  rarely  warrants  the 
expense.  .  .'•' 

The  classifier  is  arranged  so  that  the  discharge  can  be  made 
continuous  from  the  bottom  by  the  spigots  sf  and  a"  for  drawing  off 
the  particles  and  what  water  escapes  therewith.  The  velocity  of 
the  water  traveling  across  the  classifier  from  the  receiving  to  the 
discharge  end  can  be  reduced  according  to  the  amount  of  water 
fed  into  the  classifier  and  the  amount  drawn  off  at  the  bottom  flow. 

If  it  is  found  necessary  to  prevent  a  settling  of  too  small  sizes 
in  the  first  or  second  compartment  of  the  classifier  and  at  the  same 
time  effect  somewhat  of  a  separation,  an  inflow  of  clear  water  can 


TREATISE  ON  COKE  89 

be  arranged,  which  is  admitted  by  the  pipes  at  the  bottom  and 
regulated  by  the  valves  b"  and  c" .  This  inflow  is  through  pipes  of 
larger  area  than  the  outflow  through  the  spigots  zr  and  a" ,  and  the 
velocity  of  the  inflow  is  not  so  great  but  that  it  will  allow  the 
particles  of  the  sizes  desired  to  settle  down  through  its  current  and 
escape  by  the  spigots  z'  and  a" '.  This  ascending  current  may  have 
to  be  varied  from  -nj  inch  to  3  inches  a  second,  so  that  an  inlet 
pipe  of  1^  inches,  2  inches,  or  3  inches  may  be  necessary;  the  larger 
the  better  to  provide  for  increasing  or  decreasing  the  sizes  of  the 
classified  product  desired. 

A  separation  of  the  limits  of  sizes  desired  can  be  thus  effected 
by  maintaining  just  sufficient  upward  current  so  that  the  smaller 
sizes  will  not  be  permitted  to  settle,  but  the  larger  ones  will  l?e 
allowed  to  fall  through  the  current  and  be  discharged  by  the  spigots 
z'  and  a" ,  which  can  be  plugged  with  reducers  to  J  inch  or  J  inch, 
as  may  be  required  to  regulate  the  outflow,  which  will  depend  on 
the  rapidity  with  which  the  larger  sizes  accumulate.  By  testing 
the  products  under  various  flows  of  inlet  and  discharge  currents, 
it  will  be  determined  what  conditions  can  be  produced  and  accord- 
ing to  which  the  product  can  be  best  treated. 

It  may  occur  that  the  discharges  from  zf  and  a",  under  an 
upward  current,  are  entirely  impurities  and  the  overflow  at  d"  is 
entirely  pure  coal,  in  which  case  the  coal  can  be  run  directly  in  with 
other  washed  coal  to  the  settling  tank.  If  this  should  contain  much 
mud  or  .small  thin  disks  or  plates  of  impurities,  it  may  be  possible 
to  have  these  pass  off  as  suspended  matter  in  the  overflow  from 
the  settling  tank.  If,  however,  the  tendency  of  this  form  of  impuri- 
ties is  to  settle  in  the  settling  tank,  they  may  be  separated  in  the 
classifier  by  regulating  the  flow  of  water  so  that  they  will  be  carried 
out  over  the  overflow  thereof. 

If  the  light-weight  impurities  can  be  thus  disposed  of,  and  if  it 
is  possible  to  regulate  the  lower  inflow  so  as  to  have  the  heavier 
impurities  only  discharged  from  the  spigots  z'  and  a",  the  coal  may 
be  separated  therefrom  and  maintained  in  the  classifier  midway 
between  the  bottom  discharges  and  the  overflow. 

In  this  case,  there  should  be  two  sets  of  hydraulic  classifiers,  so 
that  the  current  of  water  from  the  gutter  under  the  last  screen  can 
be  turned  to  a  second  classifier  when  the  first  has  become  filled. 
The  first  can  then  be  cleaned  by  allowing  the  impurities  to  discharge 
at  the  spigots  until  the  coal  begins  to  flow.  Then  the  washed  coal 
can  be  spouted  to  the  washed-coal  trough  or  to  the  settling  tank. 
When  the  classifier  is  emptied,  it  will  be  ready  for  use  when  the 
second  classifier  has  become  filled. 

If  the  impurities  are  all  light  weight,  they  may  be  separated 
from  the  coal  by  adjusting  the  amount  of  the  bottom  discharge, 
or,  if  necessary,  of  the  inlet  current  to  such  a  point  that  the  coal 
will  be  discharged  from  the  bottom,  while  the  impurities  pass  to 
the  overflow  d" . 


90 


TREATISE  ON  COKE 


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TREATISE  ON  COKE  91 

In  all  these  adjustments  to  regulate  the  amount  of  water 
admitted  to  the  classifier,  or  to  form  an  upward  current,  or  of  the 
amount  allowed  to  discharge,  the  resulting  current  in  compartment 
y  should  be  somewhat  diminished  from  what  it  is  in  compart- 
ment #',  in  order  to  allow  a  settling  of  the  particles  in  compart- 
ment y,  which  are  smaller  than  those  settling  in  compartment  x' '. 
If  the  particles  treated  are  very  small  and  very  light  weight,  it  is 
advisable  to  make  the  compartment  y  wider  than  compartment  x? 
to  insure  a  diminution  of  the  velocity  of  current  necessary. 

WATER  REQUIRED  IN  PLANT 

Clear  Water  CUBIC  FEET   CUBIC  FEET 

4  Revolving  screens 1  cubic  foot  a  minute  =     4.0 

2  Rolls 1  cubic  foot  a  minute  =     2.0 

4  Jigs  (sand  and  slime  sizes)  .      4  cubic  feet  a  minute  =  16.0 
Classifier.  .  2  cubic  feet  a  minute  =     2.0 


Total  raised  45  feet  =  180  gallons  =  24.0  24.0 

Reused  Water  CUBIC  FEET 

igs,  i  to  ^  sizes 4  cubic  feet  a  minute  =     8.0 

igs.  |  to  §  sizes 5  cubic  feet  a  minute  =10.0 

igs,  |  to  J  sizes 5  cubic  feet  a  minute  =  20.0 


igs.  $  to  : 


sizes . .  6  cubic  feet  a  minute  =  24 . 0 


Total  raised  24  feet  =  465  gallons  =  62 . 0  62 . 0 

Total  fresh  and  muddy  water  =  645  gal.   =  86.0 

HORSEPOWER  REQUIRED 

For  Jigs 

NUMBER  SIZE  HORSEPOWER  TOTAL  HORSE- 

OF  JIGS  TREATED  PER  JIG  HORSEPOWER  POWER 

2  0  toT\  1  2.0 

2  TV  to  i  1  2.0 

2 

2 

4 

4 


2.5 
2.5 
5.0 
6.0 

Total..  ..20.0  20.0 


1  Shaking  screen 2.5 

1  Coarse  rolls 8.0 

1   Fine  rolls. . ; 3.0 

1  Picking  belt 2.0 

2  Revolving  screens,  4  feet  diameter,  1 1  feet  long 2.5       5.0 

2  Revolving  screens,  4  feet  diameter,  11  feet  long 1.5       3.0 

1  Drag  for  settling  tank 1.5 

1  Centrifugal  pump,  180  gallons,  45  feet,  3-inch  suction,  2-inch 

discharge 4.5 

1  Centrifugal  pump,  645  gallons,  24  feet,  5-inch  suction,  4-inch 

discharge 7.5 

1  Conveyer 2.0 

1  Elevator,  400  tons,  10  hours,  42-foot*  lift 2.5 


92  TREATISE  ON  COKE 

1  Elevator,  300  tons,  10  hours,  40-foot  lift   2.0 

1   Elevator,  300  tons.  10  hours,  60-foot  lift 2.4 

1   Small  elevator,  60  tons,  10  hours.  36-foot  lift  (middle  product)  1.0 

1   Small  elevator,  60  tons,  10  hours,  26-foot  lift  (refuse) 1.0 

1   Small  elevator,  60  tons,  10  hours,  30-foot  lift  (pickings) 1.0 

Total  horsepower *. 68 .  9 

Add  15  per  cent,  for  friction 10.0 

Total 78.9 

About  an  85-horsepower  engine  and  a  100-horsepower  boiler 
will  therefore  be  required. 

Crushing  Rolls. — The  coarse  rolls  are  18  inches  wide  and  19^ 
inches  in  diameter  and  corrugated  horizontally.  They  make  30 
revolutions  per  minute,  or  have  a  tangential  speed  of  about  155  feet, 
and  break  about  30  tons  to  ^-inch  size  or  70  tons  to  1-inch  size 
in  10  hours.  If  a  greater  amount  of  the  larger  size  is  to  be  reduced 
than  above,  either  larger  rolls  or  two  of  the  above  size  are  neces- 
sary. If  the  coal  sticks  to  the  rolls,  as  it  will  if  clayey  slate  is 
present,  it  is  preferable  to  use  tooth  rolls;  or  these  should  be  used 
if  the  coal  is  very  friable  and  apt  to  become  reduced  to  too  small 
sizes.  Toothed  rolls  have  a  somewhat  higher  speed  at  the  per- 
iphery, generally  about  400  to  800  feet  a  minute.  One  of  the  rolls 
of  a  pair  is  in  a  movable  box  connected  with  rods  to  steel  or  rubber 
springs,  so  as  to  allow  the  rolls  to  yield  in  case  of  hard  pieces  of 
iron,  etc.  getting  between  the  rolls  that  would  otherwise  break 
them.  A  spray  of  water  is  fed  into  the  top  of  the  rolls  to  keep 
them  clear  of  adhering  particles.  Steel  brushes  are  also  arranged 
back  of  the  rolls  to  scrape  against  them  and  remove  particles 
becoming  wedged  between  the  corrugations  or  teeth. 

The  fine  crushing  rolls  need  be  only  about  14  inches  in  diameter 
and  12  inches  wide,  but  it  is  preferable  to  have  them  as  large  as  the 
coarse  rolls,  in  the  event  of  it  being  desired  to  change  the  grading 
of  the  crushing  throughout  the  plant. 

Revolving  Sizing  Screens. — These  are  4  feet  in  diameter  and 
about  11  feet  long.  The  surface  of  the  screen  is  divided  into  four 
sections  by  five  spiders,  keyed  or  setscrewed  to  a  2yf-inch  shaft. 
Each  section  is  covered  with  perforated  sheet  metal,  requiring  four 
sheets  32  inches  by  39  inches  to  cover  each  section. 

The  screens  have  a  slope  of  8  inches  to  12  inches  in  their  entire 
length;  the  shaft  being  laid  inclined.  The  sections  of  sheet  metal 
may  be  either  riveted  or  fastened  by  bands  to  the  spiders,  the 
latter  method  being  preferable  for  despatch  in  case  of  repairs. 

Conical  screens  may  be  used,  in  which  case  the  shaft  is  laid 
level,  the  slope  of  the  sides  being  sufficient  to  assist  the  passing 
of  the  material  through  it.  The  shape  of  the  screen  sections  in 
this  case  may  give  more  trouble  in  case  of  repairs  than  with  cylin- 
drical screens.  The  speed  of  screens  is  about  22  revolutions  per 
minute,  or  the  peripheral  speed  will  be  about  270  feet  a  minute. 


TREATISE  ON  COKE  93 

The  screens  are  sprinkled  by  a  spray  of  water  from  a  IJ-inch 
pipe  located  above  the  screens  and  having  J-inch  holes  every  inch 
or  so  on  the  under  side  of  the  pipe. 

CAPACITY  OF  REVOLVING  SCREENS 

SIZE  OF  NUMBER  OF  SQUARE 

SCREEN  FEET  OF  SCREENING 

PERFORATION  SURFACE  REQUIRED 

INCHES  PER  TON  IN  10  HOURS 

U  to  2   <.'•        .32 

1    to  H 43 

f  to  1    72 

|  to    f 3.70 

*to    | 5.40 

0    to    J 18.00 

The  above  capacity  is  variable,  depending  on  the  amount  of 
other  sizes  mixed  with  the  sizes  to  be  screened.  Shaking  or  flat 
screens  have  greater  capacity  than  revolving  screens  and  are 
preferable  where  they  are  not  to  be  erected  too  high  on  the  struc- 
ture, where  they  cause  jarring  to  the  building. 

Elevators. — Large  elevators  are  best  arranged  when  buckets 
are  mounted  on  double  chain  formed  of  12-inch  or  15-inch  links 
connected  with  rods  into  which  the  links  on  either  side  of  the 
elevator  buckets  are  bolted.  The  buckets  are  bolted  to  two  straps 
hinged  from  one  rod  to  the  other.  The  elevator  frame  is  con- 
structed of  wood  with  guides  on  either  side,  which  may  be  covered 
with  strap  iron  on  which  the  elevator  rods  slide  in  the  upward 
movement  of  the  elevator,  or  the  guides  may  have  angle-iron 
sliding  pieces,  in  which  case  the  links  slide  therein  and  are  guided 
by  them.  The  sides  of  elevator  buckets  should  be  of  No.  14  Otis 
steel  and  the  front  of  No.  12  steel,  with  ribs  at  the  top,  front,  and 
sides.  Their  shape  should  be  somewhat  rounded  at  the  bottom  to 
prevent  material  becoming  wedged  therein,  but  not  too  rounded, 
or  where  they  discharge  at  the  elevator  head,  the  material  may  fall 
on  the  back  of  the  bucket  below  it  and  inside  of  the  elevator  frame. 

The  elevators  should  be  as  far  from  the  vertical  as  possible  for 
the  most  perfect  discharge  at  the  elevator  head,  otherwise  it  may 
be  necessary  to  introduce  special  devices  for  perfecting  the  dis- 
charge. The  usual  travel  for  an  elevator  is  about  100  to  150  feet 
a  minute,  although  where  they  are  vertical  or  nearly  so  a  speed  of 
200  or  225  feet  a  minute  may  be  necessary  to  insure  proper  dis- 
charge. The  slower  the  speed,  the  less  the  wear  is  on  the  elevator. 

Small  elevators  may  be  mounted  on  small  sprocket-chain,  or 
link,  belting  with  small  cast-  or  malleable-iron  buckets ;  their  speed 
may  be  150  to  200  feet  a  minute  or  less.  The  chains  supporting 
the  elevators  may  be  operated  by  sprocket  wheels  or  hexagonal 
or  octagonal  drums  driven  by  a  pulley  with  gearing.  Either  the 
upper  or  lower  set  of  sprocket  wheels  or  drums  should  be  in  an 


94  TREATISE  ON  COKE 

adjustable  boxing,  which  will  permit  of  moving  the  bearing  of 
the  sprockets  by  screws  so  as  to  tighten  up  the  elevator  chain  as 
it  becomes  worn. 

Jigs  are  preferably  built  of  wood  as  they  require  less  expensive 
foundations,  and  although  requiring  more  frequent  repairs  than 
iron  jigs  they  are  moderate  in  first  cost,  and  wearing  parts  in  iron 
jigs  being  more  expensively  replaced  than  in  wooden  jigs,  the  cost 
of  repairs  in  the  end  is  not  much  greater  in  wooden  than  in  iron 
jigs.  Jigs  treating  large  sizes  have  one  compartment  about  3  feet 
square  and  the  stroke  is  given  by  a  crank-arm  movement  making 
sixty  3-inch  or  4-inch  strokes  per  minute.  The  depth  of  the  jig 
frame  should  be  about  10  inches,  at  least,  below  the  overflow.  The 
jig  frame  may  consist  of  an  iron-bar  grating  or  of  copper  cloth  or 
perforated  metal  of  about  8  mesh.  The  discharge  for  the  lower 
product  should  be  as  automatic  as  possible  and  should  preferably 
extend  across  the  width  of  the  bed.  The  coarse  jigs  should  be 
arranged  for  treating  the  middle  product,  and  the  discharge  should 
also  be  constructed  as  above. 

Fine  jigs  should  have  two  compartments;  it  is  rare  that  three 
are  necessary.  Each  compartment  is  about  24  inches  wide  and 
32  inches  long.  These  are  provided  with  double  adjustable  eccen- 
trics so  that  the  length  of  the 'stroke  can  be  varied  as  desired. 
The  plungers  make  100  to  180  strokes  per  minute  of  2^-inch  to 
£-inch  throw  each.  The  depth  of  the  jig  frame  at  the  final  over- 
flow should  be  about  7  inches  below  it. 

It  is  also  desirable  that  the  discharge  for  the  lower  product  or 
slate  should  be  automatic  and  arranged  across  the  width  of  the 
jig  beds,  especially  for  the  larger  sizes,  although  the  refuse  in  this 
size  material  can  be  readily  withdrawn  by  a  small  slate  box  3  inches 
or  4  inches  square,  located  at  either  side  of  the  jig,  and  the  slate 
tapped  at  about  2  inches  above  the  level  of  the  jig  frame.  The 
jig  frame  is  of  wood,  built  of  J"  X  2|"  slats  with  about  2J-inch 
square  openings.  The  width  and  length  of  the  frame  are  about 
^  inch  less  each  way  than  the  space  they  occupy  in  the  jig. 

Side-plunger  jigs  are  preferable  to  facilitate  repairs,  although 
there  is  more  lost  motion  in  these  than  in  jigs  with  under  pistons 
or  jigs  in  which  the  jigging  is  done  on  a  movable  bed.  To  facili- 
tate determinations  of  speeding  jigs  it  is  preferable  to  have  the 
plungers  and  the  jig  beds  of  the  same  area.  The  bottoms  of  the 
jigs  should  all  be  steeply  sloping  to  one  or  more  mud-discharges, 
and  the  slope  sufficiently  steep  and  the  mud-valve  regularly  opened 
to  prevent  material  clogging  up  the  jig  bottoms. 

The  jigs  treating  material  from  f  inch  downwards  have  some- 
times a  bed  of  feldspar  through  which  the  jigging  is  done.  The 
feldspar  is  of  such  size  that  the  particles  of  coal  and  impurities 
will  not  fall  through  its  interstices.  The  mesh  of  the  jig  sieve  need 
then  only  be  large  enough  to  support  the  feldspar. 


TREATISE  ON  COKE 


95 


An  average  estimate  of  the  capacity  of  jigs  is  1  ton  for  each 
inch  in  width  per  10  hours.  This  is  independent  of  the  length  of 
the  jig.  A  safe,  low  estimate  to  provide  against  irregularities  in 
the  supply  of  coal  is  as  follows: 

CAPACITY  OF  JIGS 


Sizes  Treated 
by  Jigs 

Capacity  in  10  Hours 
Per  Inch  in  Width 

Width  of 
Jig 

Capacity  in  10 
Hours 

Inch 

Tons 

Inches 

Tons 

0  to  A- 

.30 

24 

7 

ft.tof 

.41 

24 

10 

itol 

.60 

24 

14 

i  to  f 

.84 

24 

20 

f  to  £ 

1.00 

24 

24 

Itol 

.  83  to  1  .  20 

36 

30  to  43 

SPEED  AND  STROKE  OF  JIGS  FOR  DIFFERENT  SIZES 


Size  of  Coal 
Inches 

Revolutions 
of  Jig 
per  Minute 

Length  of 
Stroke 
Inches 

Mesh  of  Wire 
Cloth  of 
Jig  Sieve 
Inches 

Pulley 
on  Jig 
Inches 

Driving  Pulley 
on  Main  Shaft 
Inches 

2    to  3 

50  to  60 

5i 

li 

H  to  2 

50  to  60 

4  to  5 

1     to  H 

60  to  90 

3  to  4 

Ito  I 

1  toll 

100 

2  to  3 

6X6 

20 

16  to  18 

m.1 

110 

2J 

8X8 

20 

18 

Ito     f 

120 

2 

10  X  10 

20 

20 

Ito  f 

130 

H 

10  X  10 

20 

22 

ft  to  I 

140 

f  to  1 

16  X  16 

20 

24 

•h  to  -A- 

150 

f  tof 

20  X  20 

20 

24 

0  to  ^o- 

180 

30  X  30 

20 

28 

Picking  Bands  or  Belts. — These  are  generally  4  feet  wide  and 
travel  at  a  speed  of  30  to  60  feet  a  minute.  For  sizes  from  1J  inches 
up,  and  in  quantities  of  30  tons  per  hour,  belts  should  be  15  feet  long 
plus  10  feet  more  in  length  for  each  3  per  cent,  of  material  picked  out. 

For  sizes  from  }  inch  to  li  inches,  the  belt  should  travel  at 
the  rate  of  30  feet  a  minute;  and  for  every  20  tons  an  hour,  15  feet 
length  of  belt  is  required  for  each  1^  per  cent,  of  material  picked  out. 

If  these  sizes  contain  more  than  4  or  6  per  cent,  of  impurities, 
it  is  generally  preferable  to  treat  them  by  washing. 

Drainage  Screen. — This  is  covered  with  No.  10  sheet  metal, 
preferably  copper,  to  avoid  rapid  wear,  which  will  occur  with  thin 
sheet  iron  or  steel  if  water  is  acid.  This  screen  is  geared  the  same 
as  the  other  revolving  screens. 

Settling-Tank  Dr&g. — This  is  arranged  with  wooden  pedals 
about  2  inches  thick,  4  inches  to  6  inches  deep  and  2  or  3  feet 


96  TREATISE  ON  COKE 

long,  attached  to  lugs  on  6:inch  links  every  4  feet,  and  geared,  as 
shown,  to  move  slowly  in  the  bottom  of  the  tank  and  not  rile  up 
the  settlings  too  much.  The  bottom  and  sides  of  these  pedals  have 
pieces  of  rubber  or  leather  fastened  to  them,  so  as  to  keep  closely 
in  contact  with  the  bottom  of  the  tank  along  its  bottom  and  when 
mounting  the  incline. 

Shafting. — The  main  shafting  is  2yi  inches  in  diameter  driven 
at  125  revolutions  per  minute.  It  is  desirable,  if  possible,  to  avoid 
any  shafting  at  right  angles  to  the  main  lines  of  shafting  that  will 
require  transmission  of  power  by  bevel  gears,  although  this  cannot 
always  be  avoided. 

Engine. — About  an  85-horsepower  engine  will  be  required  for 
the  size  of  plant  shown,  to  have  a  safe  allowance  of  power.  This 
should  be  mounted  with  a  10-inch  shaft  and  a  16"  X  52"  driving 
pulley.  The  engine  should  be  located  as  near  the  machinery  as 
possible  and  thus  reduce  strain  on  the  shafting. 

Boilers. — About  a  100-horsepower  boiler,  or  two  boilers  of 
50  horsepower  each,  should  be  provided  for  furnishing  the  power 
required,  with  a  safe  reserve  of  power.  The  boiler  should  be 
located  handy  to  a  point  where  the  coal  is  dumped  for  receiving 
its  supply.  This  may  be  near  either  where  the  raw  coal  or  the 
washed  coal  can  be  had. 

Location  of  Plant.— The  arrangement  of  the  plant  can  be  carried 
out  if  the  location  is  on  level  ground  or  on  a  hillside.  Unless  the 
material  arrives  at  the  plant  from  a  higher  elevation  there  is  no 
preference  in  one  location  over  the  other.  A  hillside  location  per- 
mits of  attaining  the  proper  grades  for  lines  of  screens,  jigs,  and 
other  machinery  nearer  the  natural  ground.  It  may  not  be  neces- 
sary to  support  as  much  of  the  machinery  in  the  building  as  on 
a  level  location,  nor  require  as  many  elevators,  but  the  building 
will  be  longer,  and  the  increased  number  of  floors  requiring  more 
labor  for  proper  attention  to  machinery  does  not  make  a  hillside 
location  more  preferable,  whether  its  first  cost  is  more  or  less, 
than  a  level  location.  It  is  important  that  the  floor  of  the  build- 
ing and  bottom  of  the  pits  be  located  above  the  general  level  of 
the  ground  so  that  they  can  be  readily  drained  when  desired. 

Construction  of  Building.- — Generally  a  frame  building  on  stone 
foundations  will  answer  all  purposes,  especially  if  there  is  no 
danger  in  case  of  fire  or  if  the  screening  is  done  wet,  and  heavy 
machinery  is  not  supported  high  in  the  building.  In  case  of  fire, 
or  if  the  expense  is  warranted,  an  iron-frame  building  covered  with 
corrugated  iron  is.  preferable.  If  there  is  much  heavy  machinery 
supported  in  the  structure,  the  walls  up  to  that  height  should  be 
of  stone  or  brick  and  the  balance  of  wood  or  iron.  It  is  essential 
that  the  location  of  the  machinery  and  especially  the  jigs  be  such 
that  the  building  can  be  constructed  to  allow  light  to  fall  on  them. 
For  this  purpose  the  jigs  and  such  machinery  should  be  located 
near  the  outer  walls  of  the  building,  which  will  have  windows  in 


TREATISE  ON  COKE  97 

the  sides,  or  if  the  jigs  are  located  inside,  no  machinery  should  be 
above  them  that  will  prevent  the  access  of  light  thereto  from 
windows  in  the  roof. 

COST  OF  PLANT 

Excavation,  500  cubic  yards  at  20  cents $  100 

Foundations,  stonework,  building  150  cubic  yards  at 

$1.50 225 

Stonework  of  washer  machinery  and  pits,  70  cubic 

yards  at  $2.00 140 

Boiler  and  engine  foundation  and  walls 500 

Washer  building,  lumber,  80,000  feet  B.  M.  at 

$10.00 800 

Other  finishing  lumber,  doors,  and  windows 300 

Carpenter  work 1,200 

Iron  work 300 

Coal-washing  machinery 10,000 

Erecting  (machinist  labor) 1,200 

Freight,  teaming 800 

Total $15,565 

The  cost  of  the  plant  will  vary  considerably  according  to  loca- 
tion and  distance  from  source  of  supplies.  The  above  will  be  the 
cost  where  material,  machinery,  and  labor  can  be  conveniently 
obtained.  Present  cost  of  this  plant  in  the  United  States  would 
range  from  $25,000  to  $30,000. 

COST  OF  WASHING  PER  TON,  ON  BASIS  OF  DAILY  OUTPUT 

OF  300  TONS  COSTPER 

Labor  washing  TON 

1  foreman  at  $3 . 00 $3 . 00 

3  jigmen  at  $1.50 4.50 

2  feeders  at  $1 . 00 2 . 00 

1  oiler  at  $0.75 .75 

1  engineer  and  fireman  at  $2 . 00 2 . 00 

$12.25-^300  =.040 
Slate  picking 

6  slate  pickers  at  $1 . 00 $  6 . 00-f- 300  =  .  020 

Fuel,  water,  daily 4. 00 -r- 300  =  .013 

Oil,  supplies,  etc .  .  .  .  . 2. 00-=- 300  =.006 

Maintenance  and  repairs,  etc.  to  jigs,  jig  sieves, 

screens 1,200.00  yearly  =  .010 

Emergencies,  renewals,  and  repairs  to  other 

machinery 900 . 00  yearly  =  .  015 

Total  cost  of  washing  per  ton .  =  .  104 

Improvement  of  Coal  Effected  by  Washing. — The  extent  to 
which  coal  can  be  improved  by  washing  will  depend  on  the  nature 
of  the  coal,  the  shape  of  its  particles,  the  relative  specific  gravity  of 
the  coal  and  its  impurities,  and  whether  there  are  also  present 
impurities  of  intermediate  specific  gravity,  as  bony  and  slaty  coal. 
In  treating  a  Southwestern  coal  of  the  Laramie  group  of  the 


98 


TREATISE  ON  COKE 


Upper  Cretaceous  formation  in  a  plant  similar  to  the  above,  the 
results  obtained  were  as  follows: 

The  plant  referred  to  contains  some  important  additions  for 
handling  of  the  large  coal,  intermediate  products  and  treatment 
and  settling  of  the  fines,  as  well  as  other  improvements.  The 
treatment  in  sizing  and  washing,  however,  is  similar.  Some  of 
the  very  purest  coal,  which  was  in  small  quantity  and  friable, 
analyzed  as  shown  in  No.  1,  its  ash  representing  combined  or  fixed 
ash  which  could  not  be  removed  by  any  process. 

No.  2  represents  an  analysis  of  selected  lumps  with  no  visible 
impurities  adhering  to  them. 

ANALYSES  OF  COAL 


No.  1 
Per  Cent. 

No.  2 
Per  Cent. 

Moisture                       

.39 

Volatile  combustible  matter 

20.35 

19.75 

Fixed  carbon                                                   

79.30 

64.36 

Ash                                                                

8.35 

14.65 

Sulphur                                              

.85 

The  analysis  of  ash  is  as  follows: 
PER  CENT. 

Silica 7.30  Lime 

Iron..  1.01 


PER  CENT. 

83 

Alumina. ...  .  .  5. 10 


The  specific  gravity  of  the  lightest-weight  coal  was  1.39;  of 
bony  and  slaty  coal  1.5  to  1.9;  of  slate  and  other  impurities  1.8 
to  2.3.  There  were  also  associated  thin  flakes  of  spar,  lime,  and 
slates.  The  material  used  for  washing  was  screenings  passing 
through  a  1^-inch  bar  screen,  whose  analysis,  as  well  as  that  of 
the  resulting  products,  is  shown  below,  when  the  washer  was  not 
overcrowded. 

ANALYSES  OF  COAL,  WASHED  COAL,  COKE,  AND  REFUSE 


Moisture 
Per  Cent. 

Volatile 

Combusti- 
ble Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Raw  screenings  
Washed  coal  

1.40 

.79 

19.79 
19.10 

60.25 

69.35 

17.33 
10.24 

.85 

.52 

Coke  

.43 

1.39 

83.47 

14.24 

.82 

.019 

Refuse  from  waste  box 

2.22 

15.76 

30.96 

50.12 

.93 

The  ash  in  the  screenings  was  reduced  in  washing  from  17.33  per 
cent,  to  10.24  per  cent.     The  inherent  ash  in  the  purest  coal  being 


TREATISE  ON  COKE 


99 


8.35  percent,  and  somewhat  higher  in  the  average  coal;  the  wash- 
ing, therefore,  reduced  the  ash  to  within  1.89  per  cent,  or  less  of 
the  combined  ash. 

The  yield  of  washed  coal  from  raw  coal  was  85  per  cent.,  or 
15  per  cent,  of  the  material  was  removed  as  impurities  from  the 
raw  coal,  which  con- 
sisted of  slate  and 
some  of  the  poorer 
quality  of  coal,  as 
bony  and  slaty  coal. 
The  washed  coal 
was  used  for  coke. 
The  yield  of  coke 
from  washed  coal 
was  70  per  cent.,  or 
the  yield  of  coke 
from  raw  coal  was 
59i  per  cent.,  and 
contained  14.24  per 
cent,  of  ash  with 
close  washing.  In 
other  words,  4^  gross 
tons  of  raw  coal, 
when  washed, 
yielded  3.82  tons  of 
coal,  which  was 
charged  in  a  beehive 
coke  oven  6^  feet 
high  and  12  feet 
in  diameter,  and 
burned  48  hours, 
yielding  2.67  tons 
of  coke. 

Prior  to  Washing,  pIG.  26.     ROBINSON  WASHER 

the    raw    screening 

yielded  66  to  70  per  cent,  of  coke,  much  being  lost  as  coke  ashes 

and  containing  20  to  22  per  cent,  of  ash. 


ROBINSON  COAL- WASHER  PLANT 

The  Robinson  coal-washing  machine,  Fig.  26,  consists  of  a 
wrought -iron  receptacle,  the  shape  of  an  inverted  cone  a,  surrounded 
by  a  jacket  at  the  bottom,  communication  being  made  by  a  number 
of  perforations  by  which  water  at  considerable  pressure  is  admitted 
into  the  cone.  A  vertical  shaft  having  keyed  on  it  four  revolv- 
ing arms,  or  agitators,  b  occupies  the  higher  parts  and  sides  of  the 
cone ;  this  part  of  the  machine  is  kept  in  motion  by  a  small  engine 
of,  say,  10  inches  diameter,  cylinder  fixed  at  c.  The  water  supply  d 


100 


TREATISE  ON  COKE 


from  the  cistern  e  to  the  cone  through  the  water  chamber  is  regu- 
lated by  a  valve.  A  supply  of  coal  is  admitted  from  the  small- 
coal  apparatus  down  the  slide,  or  spout,  /  into  the  open  top  of  the 
cone  filled  with  water,  the  revolving  or  stirring  motion  being  kept 
up  by  the  agitators,  and  the  upward  flow  of  water  being  con- 
tinuous ;  the  result  is  that  the  stone  and  rubbish  from  the  coal 
fall  into  a  chamber.  At  this  point,  two  slides  connected  to  neces- 
sary levers  are  inserted,  the  bottom  one  being  closed  and  the  top 
one  opened  during  the  operation  of  washing.  To  discharge  the 
rubbish,  it  is  only  necessary  to  shut  the  top  slide  and  open  the 
bottom  and  the  rubbish  falls  into  a  truck  below.  The  clean  coal 
at  the  top  passes  down  a  sieve  into  a  hopper  g  and  thence  into 
another  truck  below^  beside  the  rubbish  track,  at  will.  Immediately 
below  the  sieve  ^jiijhi  n  i1  is  fixed  a  collecting  tank  into  which  the 
water  is  drajJptfTrom  the  washed  coal  and  forced  by  means  of  a 
pulsometer  fc>fr£ft  ffie  supply  cistern  e.  An  -overflow  pipe  i  is 


arranged  between 
case  of  the  pulsomete 

It  is  estimated 
washer  cleaning  3IM.)  to 
To  this  must  be 
say  $1,500, 

The  followin analys 
washing : 


two 


isterns  to  prevent  waste  of  water  in 
the,  top  cistern  e, 

:1  machinery  complete,  for  a 
not  exceed  $2,500. 
eon  and  the  timber  work, 
$4,0(  m 
are  submitt^MpCThtfw  its  work  in  coal 


RESULTS  OF  WASHING 


Plant 

Ash 
Per  Cent. 

^  . 

Sulphur 
Per  Cent. 

r>i     1     r>       f  Unwashed.. 

11.20 

2.03 

Black  Boy|Washed 

3  84 

1.46 

{Unwashed  . 

9  35 

1.18 

Washed.  . 

4.60 

.86 

Unwashed.. 

5.95 

1.08 

Washed  

3.60 

1.00 

ITT    j            f  Unwashed 

10  10 

1  61 

Westerton(^ashede    

5  70 

1.18 

TTT    j.  A      11      j  f  Unwashed 

15.40 

1.14 

West  Auckland(Washed  

3.70 

.76 

ox    TT  1     >   f  Unwashed 

11.10 

1.92 

St.  Helen's[Washed 

2  82 

1   16 

New  Copley  /Unwashed 

11  28 

1  50 

Dusty  "Coal    \Washed                                 .      

3.83 

.84 

New  Copley  /Unwashed         

14.75 

1.61 

Coarse-small  \Washed    

2.74 

.78 

In  kindly  furnishing  the  foregoing  information  in  regard  to  this 
coal-washing  machine,  Mr.  H.  S.  Chamberlain,  President  of  Roane 
Iron  Company,  of  Chattanooga,  Tennessee,  writes:  "I  came  across 
this  machine  in  1890  while  on  a  trip  in  the  north  of  England  and 


ft  ft 

u  u 

i  Q  <n 


. 


Section  KL 


17303— in 


FIG.  27.     PLAN  OF  LETHRIG  WAS 


PLANT  AT  DOWLAIS,  WALES 


17303— in 


FIG.  28.     SECTION  or 


>  E  A  B  OF  FIG.  27 


TREATISE  ON  COKE  101 

was  so  struck  with  its  simplicity  and  effectiveness  that,  after  con- 
siderable negotiation,  I  secured  the  agency  for  the  machine  in 
this  country  and  put  one  up  at  our  colliery  at  Rockwood,  Tennessee. 
The  calculation  is  made  on  10  hours'  work  per  day;  that  is,  a  400- 
ton  machine  will  wash  400  tons  of  coal  in  10  hours,  but  really  will 
do  25  per  cent,  more  if  pushed  very  little. " 

In  the  foregoing  description  of  the  work  of  this  coal-washing 
machine,  it  is  understood  that  the  coal  used  is  the  "screenings" 
made  at  the  coal  mine  in  preparing  the  several  classes  of  lump, 
egg,  and  nut  coal  for  market.  If  the  run-of-mine  coal  is  used  for 
the  manufacture  of  coke  it  will  require  the  preparatory  processes 
of  disintegration  and  washing. 


THE  LUHRIG  WASHER,  DOWLAIS,  WALES 

Figs.  27,  28,  29,  and  30  will  convey  the  general  arrangements 
adopted  at  the  Rybnik  Collieries  in  the  location  of  the  Liihrig  coal 
washer  in  connection  with  the  coal  mine  and  coke  ovens  at  that 
place 

The  plan  shown  in  Fig.  30  is  interesting,  as  it  illustrates  the 
method  of  constructing  these  works  to  secure  the  most  economy 
in  the  several  operations.  The  processes  consist  essentially  in 
receiving  from  the  mine,  on  the  platform  or  landing  of  the  colliery 
shaft,  the  run-of-mine  coal.  It  is  then  passed  over  a  3-inch  screen, 
the  large  lumps  going  to  market,  the  screenings  being  deposited 
for  further  treatment  in  the  washing  section  of  the  plant.  This 
slack  or  fine  coal  is  then  classified  by  revolving  screens  and  washed 
in  the  usual  way.  Large  settling  tanks  are  provided  for  the  very 
fine  sludge  coal,  which  is  usually  found  valuable  in  the  manufac- 
ture of  coke.  Automatic  arrangements  have  been  made  for  storing 
the  washed  coal,  so  as  to  permit  its  becoming  somewhat  dried 
before  being  charged  into  the  coke  ovens.  The  plan  also  provides 
for  the  direct  and  economical  handling  of  the  coal  from  the  mine 
until  it  is  loaded  into  railroad  cars  for  market  or  placed  in  the 
washer  for  the  coke  ovens. 

This,  in  common  with  other  washing  machines,  will  require 
special  arrangements  to  meet  local  conditions  of  coals  to  be  treated. 
It  is  claimed  that  by  this  process  the  washed  coal  will  not  contain 
over  4  per  cent,  of  ash  at  most,  and  that  the  tailings  or  refuse  will 
retain  only  3  per  cent,  of  coal.  The  cost  of  washing  alone  is  given 
at  1^  penny;  in  the  United  States  the  cost  would  be  6  to  7  cents. 
The  capacity  of  this  washer  can  be  enlarged  to  meet  the  largest 
demands  on  its  output. 

Prof.  C.  Kreicher,  of  the  Royal  School  of  Mines,  Freiberg,  is 
quoted  as  having  approved  of  this  method  of  washing  coal. 

Description  of  the  Plant. — This  arrangement  has  been  rendered 
more  complicated  owing  to  the  machinery  having  to  be  erected  on 


102 


TREATISE  ON  COKE 


a  long,  narrow  strip  of  ground,  divided  by  an  incline  that  had  to 
be  arched  over  and  also  by  provision  having  to  be  made  for  wash- 
ing bituminous  and  steam  coal  separately. 

The  arrangement  therefore  comprises,  two  sets  of  systems,  viz.: 
(a)  The  system  for  washing  bituminous  coals;  (b)  the  system  for 
washing  steam  coals. 

(a)  The  System  for  Washing  Bituminous  Coals. — The  bitu- 
minous coal  is  brought  to  the  Shephard  machine,  which  existed 
previous  to  the  erection  of  the  new  washing  machine,  where  it  is 
crushed  by  means  of  rolls  a,  Figs.  27  and  28.  It  is  then  elevated 
by  the  elevator  c1  into  a  revolving  screen  blt  which  divides  it  into 
two  sizes,  viz.,  from  f  inch  to  0  inch,  and  from  f  inch  upwards. 

The  nut  coal,  from  f  inch  upwards,  is  raised  by  means  of  another 
elevator  c2  into  a  second  revolving  screen  62  placed  above  the 


mm^mi^^^m^    JSecUonGH 
FIG.  29.     SECTION  ON  LINE  G  H  OF  FIG.  27 

Shephard  washing  machines  d^  to  d5.  This  screen  divides  the 
coal  into  five  sizes,  which  are  washed  each  in  a  separate  machine 
of  Shephard's.  After  washing,  the  nut  coal  is  raised  by  an  ele- 
vator c3  into  bunkers  y,  situated  between  the  building  for  the 
Shephard  machines  and  the  building  for  the  crushers.  From  these 
bunkers  the  bituminous  nut  coals  may  be  discharged  into  wagons, 
when  required. 

The  fine  bituminous  coal  from  f  inch  downwards  is  transported 
by  a  current  of  water  along  a  trough  to  a  revolving  screen  66,  sit- 
uated in  the  building  of  the  new  washing  machines  erected  by 
Messrs.  Evence  Coppee  &  Company,  Engineers,  Cardiff,  Wales. 
This  screen  divides  the  coal  into  two  sizes :  from  }  inch  to  f  inch, 
and  from  0  inch  to  J  inch. 

The  coal  from  £  inch  to  f  inch  is  washed  in  two  feldspar  machines 
£14  and  £ie»  Figs.  27  and  28,  placed  immediately  below  the  screen; 


TREATISE  ON  COKE  103 

and  the  coal  from  0  inch  to  J-  inch  is  conveyed  in  a  trough  by  a 
current  of  water  to  the  pointed  trough  /2,  shown  on  the  plan  and 
situated  in  the  adjoining  room  of  the  new  building.  It  is  here 
divided  into  six  sizes,  each  of  which  is  washed  separately  in  the 
feldspar  machines  gt  to  ge  placed  next  to  the  pointed  trough. 
The  f-inch  and  upwards  bituminous  coal  is  sent  from  the  elevator 
raising  the  washed  coal  into  a  crusher.  After  being  crushed,  it 
meets  the  small  steam  coal  in  a  bunker  situated  below  the  crusher, 
from  which  an  elevator  raises  the  coals,  already  partly  mixed,  to  a 
screw  placed  on  the  bunkers  erected  in  front  of  the  crushing  depart- 
ment. The  screw  o  finally  mixes  the  two  coals  and  distributes 
them  into  bunkers  15  and  /6,  from  which  ultimately  the  small 
mixed  coal  is  taken  to  the  coke  ovens. 

(b)  The  System  for  Washing  Steam  Coals. — The  steam  coal  is 
also  treated  in  the  new  washing  arrangement.  Arriving  in  wagons, 
it  is  tipped  into  a  bunker  h  in  front  of  the  new  building,  Figs.  27, 
28,  and  29,  from  whence  an  elevator  2\  raises  it  into  a  large  revolv- 
ing screen  b3;  this  screen  divides  the  coal  into  six  sizes,  one  of 
which  is  0  inch  to  f  inch,  and  five  others  varying  from  If  inches 
to  f  inch.  The  last  five  sizes  are  each  washed  separately  in  five 
machines  ]\  to  /5,  ranged  on  the  second  floor,  from  whence  the 
coal  is  run  off  on  to  reciprocating  screens  k1  to  k4  for  the  purpose 
of  draining  off  the  water.  The  dry  coal  drops  into  bunkers  /j  to  /4, 
from  whence  it  may  be  sent  away  in  railway  wagons. 

When,  however,  the  five  sizes  are  required  for  coking,  the  coal 
is  sent  by  a  trough  into  a  revolving  screen  b4  fixed  next  to  the 
crushers,  from  whence  it  is  taken  in  a  dry  state,  by  means  of  a 
screw,  to  the  disintegrators  x.  The  water  draining  off,  and  which 
contains  small  coal  in  suspension,  coming  from  the  drying  revolv- 
ing screen  and  the  reciprocating  tables,  returns  to  the  feldspar 
machines. 

The  fine  coal  from  0  inch  to  f  inch  from  the  large  revolving 
screen  63  enters  another  revolving  screen  65,  which  divides  it  into 
two  sizes,  |  inch  to  J  inch  and  }  inch  to  0  inch.  The  first  size  is 
washed  in  two  feldspar  machines  g13  and  g15  situated  in  the  large 
revolving  screen  building,  while  the  second  and  smallest  is  carried 
by  water  in  a  trough  to  a  pointed  trough  /t  similar  to  that  used  for 
dividing  the  bituminous  coal.  The  pointed  trough  divides  the  coal 
into  six  sizes,  each  of  which  is  washed  in  separate  machines  g7  to 
g16.  All  the  fine  washed  coal  in  a  feldspar  machine  runs  together 
into  a  large  basin,  from  whence  an  elevator  i4  with  perforated 
buckets  raises  it  to  the  top  of  the  bunker  q.  The  small  coal  may 
be  bunkered  if  desired;  if  not,  it  may  be  sent  by  a  transporter  to 
the  crushing  building,  where  it  is  remixed  with  the  crushed  bitu- 
minous and  steam  coal. 

The  overflow  of  small  coal  from  the  small-coal  basin  runs  first 
into  a  long  trough  provided  with  a  screw,  and,  as  the  small  coal 
settles,  the  screw  brings  back  the  coal  to  the  common  small-coal 


104 


TREATISE  ON  COKE 


TREATISE  ON  COKE  105 

basin,  while  the  water  runs  into  settling  tanks  or  clarifiers  m  m. 
These  clarifiers  are  three  long-pointed  troughs  provided  with  a 
screw  situated  underneath.  The  dirty  water,  after  having  passed 
through  the  clarifiers,  returns  to  the  well  of  the  centrifugal  pump  t, 
by  which  it  is  sent  back  and  redistributed  to  the  washers.  The 
mud  settling  in  the  clarifiers  drops  by  gravity  into  the  trough  of 
the  screw,  which  transports  it  to  the  elevator  is  situated  at  one 
end  of  the  clarifiers,  which  raises  the  mud  and  drops  it  into  bunk- 
ers nl  and  n2. 

The  arrangement  described  above  is  washing  100  tons  of  coal 
per  hour. 

REFERENCE  TO  THE  DOWLAIS  WASHING  ARRANGEMENT 

On  Figs.  27,  28,  and  29  a,  are  crushing  rolls;  blt  revolving  screen 
for  bituminous  coal,  0  inch  and  J  inch;  62,  revolving  screen  for  bitu- 
minous coal,  |  inch  and  upwards;  63,  revolving  screen  for  steam 
coal,  0  inch  to  f  inch  and  upwards ;  65  and  66,  small  revolving  screens 
for  fine  coal;-64,  revolving  screen  for  drying  nuts  for  coking;  clt  c2, 
c3,  bituminous-coal  elevators;  dlt  d2,  d3,  d4,  d5,  Shephard's  washing 
machines;  fl  and  /2,  spitzkasten,  for  classifying  fine  coal;  gl  to  g6, 
washers  for  fine  bituminous,  from  0  inch  to  J  inch,  feldspar  cases; 
£14  to  g16,  washers  for  fine  bituminous,  from  J  inch  to  J  inch,  feldspar 
cases;  g7  to  gl2,  feldspar  washers,  for  fine  steam  coal,  0  inch  to 
J  inch;  g13  and  g15,  feldspar  washers  for  fine  steam  coal,  J  inch 
to  f  inch;  h,  basin  receiving  steam  coal  from  wagons;  ilt  elevator 
raising  steam  coal  to  screen  63;  i2,  elevator  raising  mixed  coal 
to  transporter  for  crushing;  i3,  elevator  raising  shale;  *4,  elevator 
raising  interstratified  coal;  *5,  elevator  raising  slimes  from  clari- 
ficator;  ;\  to  ;5,  machines  for  washing  coarse  coal,  f-  inch  upwards; 
k,  reciprocating  screens;  /j  to  /4,  bunkers  for  washed  nut  coal; 
/5  to  /„,  bunkers  for  fine  washed  coal,  f  inch  and  downwards; 
m  clarificator,  or  settling  tanks;  n,  slimes  bunkers;  o,  worm  for 
transporting  coal  to  p^  to  pa  or  to  x;  pl  to  p12,  bunkers  for  crushed 
washed  coal  to  Coppee  ovens;  q,  bunkers  for  interstratified  coal; 
fi»  r2>  fs»  basins;  s,  driving  engine  for  washing  machines;  t,  centrif- 
ugal pump;  u,  water  pipes  for  supply  to  washers,  etc.;  v,  small 
engine  for  driving  elevator  and  worm  of  clarifier;  w,  disintegrator 
engine; .x,  disintegrators;  y,  bunker  for  washed  crushed  coal  delivery 
in  wagons;  z,  driving  engine. 

Results  Obtained  at  Dowlais  Washery. — The  important  ques- 
tions to  consider  in  coal  washing  are,  generally  speaking,  three': 
(1)  to  wash  the  coal  clean,  so  as  to  remove  all  impurities,  as  far  as 
that  is  possible;  (2)  not  to  allow  any  coal  to  pass  away  with  the 
impurities;  and  (3)  to  wash  the  coal  cheaply.  As  to  the  first 
point,  which  is  very  important,  it  would  be  reasonable  to  know 
the  limit  to  which  the  impurity  might  be  removed  from  the  coal. 
It  was  thought  there  was  only  one  way  of  settling  that  question,  and 


106  TREATISE  ON  COKE 

that  was  to  ascertain,  by  analysis,  the  yield  in  ash  of  the  pure  coal 
or  the  ash  that  could  not  be  removed  by  mechanical  means,  as  it 
was  certain  that  even  the  purest  picked  coal  would  still  contain  a 
certain  amount  of  impurities  so  intimately  combined  with  the  fuel 
that  even  with  the  best  system  of  washing  it  would  be  impossible 
to  remove  it.  In  order  to  estimate  the  ash  thus  intimately  com- 
bined with  the  coal,  the  best  way  was  to  pick  out  small  lumps,  or 
nuts,  of  pure  coal  and  submit  them  to  analysis  by  incineration. 
The  method  was  so  simple  that  it  might  be  carried  out  by  any  one 
with  a  little  practice,  even  without  any  knowledge  of  chemistry, 
and  would  enable  him  to  estimate  the  contents  of  the  ash  in  pure 
picked  specimens  of  coal — a  result  that  might  be  taken  as  the 
absolute  limit  of  the  greatest  amount  of  purity  to  be  obtained  by 
washing.  Some  coals  were  so  pure  that  pieces  would  not  show 
more  than  1.5  per  cent,  of  ash;  others  were  so  dirty  that  the  ash 
amounted  to  10  per  cent.  Fortunately,  the  last  class  of  coal  was 
scarce  in  this  country. 

The  table  on  page  107  shows  the  results  of  4  months'  coal  wash- 
ing in  the  washing  machine  erected  at  Dowlais,  and  described  in 
the  preceding  pages. 

In  regard  to  the  results  of  the  Dowlais  washing,  as  per  details 
submitted  in  full  in  this  table,  the  average  figures  are  typical  of  the 
results  of  the  5  months'  work.  The  steam  coal,  in  its  unwashed 
condition,  contained  an  average  of  15.9  per  cent,  of  ash  and  the 
unwashed  bituminous  coal  25  per  cent,  of  ash.  The  mixture  of 
these  two  coals  in  the  proportion  of  half  and  half  gave  an  average 
of  20.4  per  cent,  of  ash,  and  the  mixed  coal,  after  washing,  con- 
tained 5.9  per  cent,  of  ash,  while  the  coke  made  with  that  mixture 
gave  an  average  of  8.9  per  cent.  In  the  month  of  January  the  coke 
made  with  that  mixture  of  washed  coal  gave  only  7.5  per  cent,  of 
ash.  These  might  be  considered  as  fair  average  figures.  During 
the  first  3  months  after  starting — viz.,  September,  October,  and 
November,  comprised  in  the  table — the  washing  and  sorting  were 
not  as  perfect  as  in  the  subsequent  months;  therefore,  the  figures 
for  the  month  of  January  were  taken  as  being  a  fair  statement  of 
the  result. 

Now,  with  respect  to  the  second  point  that  required  consider- 
ation, Viz.,  to  conduct  the  operation  so  as  not  to  remove  any  por- 
tion of  the  free  coal  with  impurities  or  with  the  shale  itself.  The 
best  way  to  ascertain  that  the  shale  is  practically  free  of  coal  is 
by  taking  a  sample  of  the  shale  washed  out,  dividing  it  into  two 
parts;  one  part  is  then  submitted  to  a  careful  washing  in  an  ordi- 
nary washing  basin  in  order  to  remove  all  the  particles  of  coal 
from  it,  and  the  shale,  after  being  dried,  is  then  incinerated;  the 
difference  between  the  weight  of  the  ash  and  100  will  give  the  yield 
of  volatile  matters.  Now,  take  the  other  sample  of  shale  and  dry 
and  incinerate  it ;  the  difference  between  the  weight  of  the  ash  and 
100  will  give  the  yield  of  volatile  matters  in  the  shale  plus  that  in 


TREATISE  ON  COKE 


107 


Percentage  of  Ash 

TOM?pKoui 

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O  00             l>        00 

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snouidmijg  JJBJJ  puB 
tUBa^c;  J{BJJ  jo  aan^xii\[ 

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Percentage  of  Ash  in  Washed  Coal 

1 

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IH 

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Bituminous  Coal 

2 

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Steam  Coal 

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COCOCO             CO        CO 

In  Nut-Coal 
Washers 

1 
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1884 
September  and  October. 
November  
December  

1885 
January  

Average  

108  TREATISE  ON  COKE 

the  free  coal  contained  in  the  shale.  Deducting  the  result  of  the 
incineration  of  the  rewashed  portion  of  shale  from  the  last  result  of 
incineration,  the  difference  will  show  the  free  coal  carried  away 
with  the  shale. 

In  the  feldspar  washery  of  the  Coppee  system,  the  free  coal  in 
the  shale  varies  from  1^  per  cent,  to  5  per  cent.  The  yield  in  ash 
in  the  shales  varies  not  only  from  district  to  district,  but  from  a 
seam  of  coal  to  a  seam  of  coal.  However,  we  may  state  that, 
according  to  many  hundreds  of  analyses  of  the  shales  of  South 
Wales,  the  ash  in  them  amounts  to  from  66  per  cent,  to  75  per  cent. 
Some  Lancashire  shales  yield  only  about  47  per  cent,  of  ash.  The 
cost  of  washing,  including  labor  and  all  charges,  except  interest 
on  capital,  does  not  exceed  3  pence  per  ton  of  washed  coal. 

The  following  are  a  few  analyses  of  the  Clifton  and  Kersley 
small  coal  in  an  unwashed  state — analyses  that  were  made  previous 
to  the  erection  of  the  washery : 

PER  CENT.  OF  ASH 

Gannel  coal  contained 30 . 340 

Doc  mine  coal  contained 16 . 450 

Pure  picked  nuts  of  cannel  coal  contained 8.200 

Pure  picked  nuts  of  Doc  mine  coal  contained 2 . 740 

Mixing  the  two  above  coals  in  equal  quantities,  the 

average  ash  in  the  mixture  was 23 . 395 

Average  of  intimately  connected  ash  with  nuts  in  the 

mixture  of  equal  parts  was 5 . 470 

After  3  months'  washing,  a  few  samples  of  small  coal 

taken  and  analyzed  gave  in  average -. . 6 . 550 

So  that  the  washed  coal  differed  from  the  absolutely  pure  coal 
by  1.08  per  cent,  of  ash  only,  which  may  be  considered  an  exceed- 
ingly satisfactory  result. 

LUHRIG  WASHER,  NELSONVILLE,  OHIO 

The  following  is  a  description  of  a  Ltihrig  coal  washery  for  fine 
coal  screenings,  designed  and  equipped  in  1901  by  the  Link-Belt 
Machinery  Company,  of  Chicago,  Illinois,  for  the  Buckeye  Coal  and 
Railroad  Company,  of  Nelson ville,  Ohio,  that  has  a  capacity  of 
100  tons  per  hour.  The  design  was  to  assemble  the  screenings 
from  a  number  of  coal  mines  in  the  Hocking  Valley  field  to  a  con- 
venient point,  unload  them,  wash  them,  and  send  the  cleaned  coal 
to  market  in  fine  sizes,  known  in  the  market  as  domestic  egg, 
No.  1  nut,  No.  2  nut,  No.  3  fine,  and  No.  4  fine. 

The  coal  screenings  were  to  be  delivered  either  in  hopper-bottom 
or  gondola  cars.  Hopper  cars,  it  was  believed,  could  be  unloaded 
on  one  track  at  the  rate  of  100  tons  per  hour,  and  track  No.  1, 
Figs.  31  and  32,  was  set  apart  for  this  purpose.  Under  this  track 
there  was  constructed  a  concrete  hopper  about  40  feet  long  and 
holding  a  carload  of  coal.  From  this  hopper,  the  coal  was  taken 
to  the  elevator  a  by  means  of  the  right-and-left  screw,  b,  as  it  was 


T-T  \cnqtne  ( 

- 


1 7303  ~i 


FIG.  31.     LtiHRiG  WASHERY  AT  NEL 


-       . 

i         r  i  iiji  ^ 

r;vt^-:t;:t -ttj^l 

r  _u  _  .gri.      i    _  _  ^V  _^^_Mir  zp  -  - 

"~rii1,  l~ul£-I9-J 


LLE,  OHIO.     (END  ELEVATION.) 


r? 


&;*. 

..*... 


»        Track  rtqoper 
i 

fvVV'^VV-^'-VVV-^'- 
cinti-  ------- =^ --=---- ---T* 


i  ^-^  r 


17303—in 


FIG.  32.     LUHRIG  WASHERY  AT  NE 


VILLE,  UHIO.     (SIDE  ELEVATION.) 


rl 


TREATISE  ON  COKE  109 

not  found  possible  to  unload  100  tons  per  hour  on  one  track. 
With  the  application  of  a  screw  unloader  and  an  additional  track, 
No.  2,  this  difficulty  was  removed. 

Elevator  a  delivers  the  coal  into  a  pair  of  jacketed  screens  c,  c 
that  classify  the  coal  into  three  sizes  of  coarse  coal  and  one  size 
of  fine  coal.  The  inner  jacket,  with  l^-inch  holes  makes  domestic 
egg;  the  middle  jacket,  with  1-inch  holes,  makes  No.  1  nut;  the 
outer  jacket,  with  f-inch  holes,  makes  No.  2  nut.  The  domestic 
egg  and  No.  1  sizes  are  distributed  into  the  respective  nut-coal  jigs 
by  means  of  the  conveyers  d,  d  while  the  No.  2  nut  falls  direct 
into  the  nut-coal  jigs.  From  the  nut-coal  jigs  on  the  third  floor, 
the  washed  nut  coals  are  delivered  direct  into  their  respective 
bins  by  means  of  the  bumping  screens  e,  which  are  placed  directly 
over  the  washed-coal  bins,  draining  some  of  the  water  from  the 
coal  and  allowing  the  clean  nut  coal  to  fall  direct  into  the  ship- 
ping bin  without  further  handling.  A  spray  of  clean,  fresh  water 
thrown  on  the  coal  before  it  leaves  the  bumping  screen  brightens 
it  considerably. 

The  washed-coal  bins  are  nine  in  number,  and  are  arranged  in 
a  row  over  the  shipping  track.  There  are  two  bins  for  each  of 
the  three  coarse  coals,  one  for  No.  3,  one  for  No.  4,  and  one  for 
Nos.  3  and  4,  mixed.  An  additional  bin  has  been  provided  for 
the  refuse,  which  is  loaded  into  hopper-bottom  cars  and  used  by 
the  railroad  managers  for  filling.  Each  bin  holds  30  tons  and  a 
car  of -nut  coal  can  be  loaded,  one  half  from  each  of  the  two  bins. 
The  nut-coal  bins  need  never  be  less  than  half  full,  reducing  the 
breakage  of  the  clean  nut  coal  to  a  minimum. 

The  refuse  from  the  jigs  is  gathered  by  the  screw  conveyer  /, 
raised  out  of  the  water  by  the  perforated  bucket  elevator  g,  and 
delivered  direct  into  the  refuse  bin  over  the  shipping  track.  The 
water  from  the  nut-coal  jigs,  drained  out  of  the  coal  by  the  bumping 
screens  e,  flumes  the  fine  coal  from  the  outer  jackets  of  the  screens 
c,  c  into  the  fine-coal  jigs  h  by  means  of  the  grading  box  i,  which 
hydraulically  grades  the  coal  to  the  jigs  for  better  washing.  From 
h,  the  clean  fine  coal  is  flumed  to  the  draining  screen  /,  which  has 
£-inch  holes  in  it.  It  not  only  drains  the  water  from  the  coal,  but 
also  screens  out  the  No.  3,  f-inch  to  J-inch  sizes,  from  the  No.  4  size. 

The  No.  3,  from  end  of  screen  /,  is  lifted  into  its  shipping  bin 
by  means  of  the  perforated  elevator  k.  The  ultimate  refuse  from 
the  bottom  of  the  jigs  is  recovered  by  the  refuse  recovery  screw  m 
and  lifted  into  the  refuse  bin  over  the  shipping  tracks  by  the  per- 
forated  bucket  elevator  n.  The  sludge,  or  No.  4  coal,  being  all 
the  coal  below  J  inch,  is  recovered  by  the  Luhrig  sludge  recovery  o 
and  lifted  into  its  shipping  bin  by  the  sludge  elevator  p. 

The  water  is  circulated  by  a  10-inch  centrifugal  pump  q.  The 
power  plant  is  located  in  a  separate  brick  building  from  which 
the  power  is  transmitted  to  the  washery  by  means  of  rope 
transmission  r.  Two  66'  X  18'  boilers  furnish  the  steam  to  a 


110 


TREATLSE  ON  COKE 


150-horsepower  double  Erie  automatic  engine  and  to  a  small 
electric-light  engine.  The  screw  conveyer  5  takes  No.  4  washed 
coal  direct  from  the  shipping  bins  to  the  front  of  the  boilers. 

The   following    table    summarizes    some    approximate   figures 
regarding  the  operation  of  this  plant: 


Name  of  Coal 

Size  of  Screen 
Inches 

Proportion 
Per  Cent. 

Free  Water 
Per  Cent. 

Domestic  egg                

H 

16 

1 

No    1  nut                  

1£  to  1 

21 

1 

No   2  nut          

1  to  f 

17 

2 

No   3  fine 

f  to  1 

20 

4 

No   4  fine 

1  to  0 

14 

9 

Waste                                     

12 

The  amount  of  free  water  was  obtained  by  weighing  a  car  of 
wet  coal  as  it  came  from  the  shipping  bins  and  then  allowing  it  to 
stand  on  a  siding  to  drain  until,  by  repeated  tests,  it  no  longer 
showed  any  appreciable  loss  in  weight. 


LUHRIG  WASHERY  AT  PUNXSUTAWNEY,  PENNSYLVANIA 

The  Liihrig  coal  washery,  erected  near  Punxsutawney,  Jeffer- 
son County,  Pennsylvania,  is  one  of  the  large  modern  washers  for 
the  cleaning  of  coal  for  the  manufacture  of  coke.  It  has  a  capacity 
of  75  tons  per  hour  as  designed  and  equipped  in  1897  by  the  Link- 
Belt  Machinery  Company,  of  Chicago,  Illinois.  The  objects  sought 
to  be  obtained  in  this  plant  are:  (1)  To  provide  clean  coal  for  the 
beehive  coke  ovens;  (2)  to  be  prepared  to  ship  clean  nut  coal  for 
fuel  purposes  if  the  market  conditions  make  it  desirable  to  do  so. 
Fig.  33,  (a),  (6),  and  (c),  shows  three  views  of  the  general  arrange- 
ment of  the  machinery  and  main  timbers  in  the  supporting  struc- 
ture, with  many  details  omitted  to  avoid  confusion  of  lines.  A 
raw-coal  bin,  not  shown  on  the  drawings,  holding  2,000  tons,  was 
provided  to  receive  the  accumulation  of  coal  from  the  mine,  so  as 
to  make  mine  and  washery  independent  of  each  other  to  the  extent 
of  2  days'  full  run.  In  this  bin  or  receiver  the  run-of-mine  coal 
is  stored,  after  having  been  broken  to  nut-coal  size  by  two  Bradford 
breakers.  From  this  raw-coal  bin  the  coal  is  taken  as  required, 
by  a  Dodge  chain  conveyer,  and  placed  in  the  raw-coal  hopper  a; 
from  this  it  is  taken  by  the  elevator  b  to  the  top  of  the  building 
and  delivered  into  the  triple  jacket  screen  c.  This  screen  has 
jackets  with  1^-inch,  1-inch,  and  £-inch  holes,  reading  from  within 
out,  making  Nos.  1,  2,  and  3  nut  coals  and  a  finer  coal,  which  is 
all  that  passes  through  the  £-inch  holes  in  the  outer  jacket.  The 
three  sizes  of  coals  are  kept  separate  and  are  apportioned  among 
the  seven  nut-coal  jigs  d,  according  to  their  respective  quantities. 


—  X.  --V- 
4VK 


J, 


17303— in 


FIG.  33.     LtfHRiG  WASHERY  . 


UNXSUTAWNEY,  PENNSYLVANIA 


TREATISE  ON  COKE  111 

From  these  nut-coal  jigs,  the  cleaned  coal  is  flumed  direct  into 
the  six  shipping  bins  Nos.  1,  1,  2,  2,  3,  3,  in  (a);  the  water  being 
drained  from  the  coal  by  means  of  the  bumping  screens  e.  If  this 
nut  coal  is  not  to  be  shipped  as  fuel,  but  is  to  be  used  for  making 
coke,  it  is  flumed  to  the  second  nut-coal  elevator  /,  which  has  per- 
forated buckets,  and  drains  the  water  from  the  coal  as  it  is  lifted 
to  the  Link-Belt  coal  crusher  g.  The  fracture  of  the  coal  being 
cubical  and  the  slate  interleaved  in  flat  condition,  this  crusher 
frees  the  slate  from  the  coal,  the  product  passing  through  the 
screen  h;  the  rejections  from  the  screen,  which  has  J-inch  round 
holes,  are  nearly  all  flat  slate  pieces  and  are  discarded. 

It  will  be  noticed  that  the  nut-coal  jigs  are  on  the  third  floor. 
On  the  second  floor  is  a  row  of  twelve  fine-coal  jigs  t — Luhrig 
feldspar  jigs.  Six  of  these  are  used  to  wash  the  fine  coal  that  is 
passed  through  the  holes  in  the  outer  jacket  of  screen  c,  while  the 
other  six  are  used  to  wash  the  washed  nut  coal  that  has  been 
crushed  by  g  and  screened  through  the  holes  in  h. 

The  clean  coal  from  the  twelve  fine-coal  jigs  is  flumed  to  the 
draining  screen  i,  which  has  ^-inch  holes.  The  discharges  from 
the  end  of  this  screen  are  the  final  clean  coal  and  are  lifted  by 
means  of  the  perforated  bucket  elevator  /  to  the  top  of  the 
2,000-ton  washed-coal  draining  bin  k,  into  which  it  is  distributed 
by  means  of  the  Dodge  chain  conveyer  /. 

The  slate  valves  in  the  nut-coal  jigs  d  are  so  set  as  to  reject  as 
primary  refuse  all  pieces  of  coal  that  are  contaminated  with  slate 
or  other  foreign  matter.  This  refuse  is  gathered  from  the  seven 
jigs  by  means  of  a  screw  conveyer  m,  and  lifted  out  of  the  water 
by  the  perforated  elevator  n  and  dropped  into  crusher  o,  which  is 
the  same  make  as  crusher  g.  From  o,  it  is  elevated  by  means  of 
the  intermediate  elevator  p  and  screened  by  q.  Here  again  flat 
pieces  of  slate  are  separated  and  all  that  passes  through  the  £-inch 
holes  in  q  is  rewashed  in  the  Luhrig  feldspar  rewashing  jigs  r. 
These  jigs  are  similar  to  the  fine-coal  jigs,  but  the  relative  areas  of 
plungers  and  screen  surface  are  different.  The  clean  coal  recovered 
by  these  jigs  is  lifted  by  elevator  5  into  the  rewashed-coal  bin  as 
shown  on  (a).  The  final  refuse  that  passes  through  the  feldspar 
bed  in  the  fine-coal  jigs  /  and  the  rewashing  jigs  r  goes  into  the 
refuse  recovery  u. 

A  great  quantity  of  water  is  required  about  this  plant  for 
washing  the  coal  and  refuse,  but  this  water  must  be  recovered  and 
used  over  and  over.  If  allowed  to  run  away,  it  would  not  only 
require  a  large  fresh -water  supply,  but  it  would  carry  away  with 
it  a  quantity  of  fine  coal,  as  well  as  damage  adjoining  properties 
by  flooding  them  with  fine  coal  and  refuse.  All  the  water  used  in 
the  washery,  therefore,  except  such  portion  as  is  carried  away  with 
the  wet  coal  and  dirt,  is  finally  gathered  into  the  sludge-recovery 
tank.  At  v  is  an  8-ineh  centrifugal  pump  taking  its  suction  from 
the  near  end  of  the  sludge  recovery,  and  the  main  stream  of  water 


112  TREATISE  ON  COKE 

is  lifted  to  the  nut-coal  jigs  and  used  in  washing  the  nut  coal.  All 
the  water  drained  from  the  nut  coal  by  e  or  /  is  used  to  flume  the 
fine  coal  "from  the  outer  jacket  of  c  into  the  fine-coal  jig  t.  Some 
additional  water  from  the  pump  v  being  required,  all  the  water 
drained  from  the  final  washed  coal  by  i  and  5  flows  into  the  pit  at 
the  end  of  the  sludge  recovery  tank. 

This  sludge  recovery  consists  of  a  large  tank  80  feet  long, 
11  feet  wide,  and  12  feet  deep.  At  one  end,  in  which  stands  the 
sludge  elevator  w,  the  pit  is  8  feet  deep.  In  the  bottom  of  this  tank 
there  is  a  scraper  conveyer  having  three  chains  and  scrapers  of  the 
full  width  of  the  tank ;  this  moves  very  slowly  and  scrapes  all  the 
fine-coal  settlings  to  the  elevator  pit.  All  the  water  entering 
the  sludge  recovery  does  so  at  the  pit  end  and  is  taken  out  at  the 
opposite  end  by  the  centrifugal  pump.  The  fine  coal  thus  settled 
consists  of  that  which  escapes  through  the  holes  in  screen  i  and 
elevator  buckets  s,  and  is  lifted  by  w  and  delivered  into  the  coking- 
coal  bin  by  conveyer  /,  thus  mixing  it  thoroughly  with  the  coal 
elevated  by  /.  The  water  that  has  been  used  to  flume  the  refuse 
from  the  bottoms  of  the  jigs  flows  to  the  refuse  recovery  u.  This  is 
a  Y-shaped  tank  in  which  a  screw  conveyer  x  gathers  the  settlings 
to  a  final  refuse  elevator  y,  which  has  perforated  buckets  and 
delivers  the  final  refuse  into  its  bin  to  be  removed  from  the  plant. 
The  water  overflowing  from  the  refuse  recovery  goes  into  the 
sludge  tank  and  is  again  used. 

The  table  of  analyses,  on  page  113,  of  coal  before  and  after 
washing,  is  taken  from  the  experience  of  the  manufacturers  of  the 
Liihrig  washers,  the  Link-Belt  Machinery  Company. 

An  excellent  example  of  what  can  be  accomplished  through  the 
washing  of  coal  is  furnished  by  the  results  obtained  at  the  Montana 
Coal  and  Coke  Company's  plant  at  Aldridge,  Montana,  as  described 
by  Mr.  J.  V.  Schaefer  in  Mines  and  Minerals  for  December,  1903. 
The  coal  there  mined  is  very  friable;  and  in  a  test,  74  per  cent,  of 
the  coal  passed  through  a  J-inch  mesh  sieve  and  contained  15.7 
per  cent,  ash;  15.8  per  cent,  passed  over  a  J-inch  mesh  arid  through 
a  J-inch  sieve  and  contained  25.6  per  cent,  ash;  the  10  per  cent, 
that  went  over  the  J-inch  sieve  contained  40.8  per  cent.  ash.  A  test 
of  a  sample  of  the  coal  that  had  passed  through  a  ^-inch  mesh 
and  over  a  J-inch  mesh  shows  that  32  per  cent,  floated  in  a  solu- 
tion having  a  specific  gravity  of  1.31  and  contained  7.2  per  cent, 
ash,  while  68  per  cent,  sank  and  contained  41.5  per  cent.  ash. 

This  coal  was  washed  in  two  jigs.  As  a  result  of  the  first 
jigging,  61  per  cent,  of  the  mine  product  was  obtained  that  was 
suitable  for  coking  and  contained  from  10  to  11  per  cent.  ash. 
The  refuse  from  this  first  jigging  was  rejigged,  and  from  this 
material  3  per  cent,  of  the  mine  product  was  obtained  as  middlings, 
which  was  used  for  fuel  under  the  boilers  at  the  plant  and  con- 
tained 18  to  20  per  cent,  ash,  while  36  per  cent,  of  the  mine  product 
was  rejected  as  refuse  and  contained  60  to  68  per  cent.  ash. 


TREATISE  ON  COKE  113 

ANALYSES  OF  COAL  BEFORE  AND  AFTER  WASHING 


Washery 

Before  Washing 

After  Washing 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Alexandria  Coal  Co     Greensburg   Pa 

10.60 

8.60 

37.04 
12.88 

9.48 

9.19 

18.21 
21.75 
9.65 
31.08 
25.60 

7.56 

16.30 

25.30 
15.80 
18.74 

38.00 
18.00 
13.77 

16.30 
25.00 
5.63 
4.69 
5.41 

14.29 

1.139 
1.30 

3.53 

.78 

1.43 

5.07 

.77 

.34 

1.53 
.57 

1.90 
3.34 

1.05 
.57 

1.64 
1.50 
1.56 

1.32 

6.21 

9.50 
5.45 

11.00 
7.65 

4.85 

8.34 

11.72 
9.14 
5.30 
12.25 
8.50 

4.41 

9.70 

8.50 
8.00 
5.56 

8.90 
4.20 
4.30 

9.70 
8.00- 
2.25 
3.25 
4.63 
6.24 
5.72 

.617 

.850 
1.030 

2.870 
.690 

1.100 

4.540 
.480 

.550 

1.140 
.400 

.870 
2.400 

.890 
.400 

1.110 
1.680 
1.120 
1.010 
.820 

Coke  made  from  this  washed  coal  

Rochester  and  Pittsburg  Coal  and  Iron  1 
Co     Punxsutawney   Pa                              / 

Skagit  Coal  and  Coke  Co.,  Cokedale,  Wash. 
Central  Coal  and  Iron  Co.,  Central  City,  Ky. 
New  Ohio  Washed  Coal  Co.,  Carterville,  1 
111     No    1  mine                                 ...      / 

New  Ohio  Washed  Coal  Co.,  Carterville,  \ 
111     No   2  mine  .    .  .  .    J 

Cambria  Mining  Co.,  Cambria,  Wyo  
Dayton  Coal  and  Iron  Co.,  Dayton,  Tenn. 
Crows  Nest  Pass  Coal  Co.,  Ferriie,  B.  C.  .. 
Western  American  Co.,  Fairfax,  Wash..  .  . 
Montana  Coal  and  Coke  Co.,  Horr,  Mont  . 
Kanawha  and  Hocking  Coal  and  Coke  \ 
Co    Harewood,  W.  Va  J 

Northwestern  Improvement  Co.,  Roslyn,  \ 
Wash                                                              J 

Rocky  Fork  Coal  Co.,  Red  Lodge,  Mont... 
Luhrig  Coal  Co     Zaleski   Ohio 

Belt  Mountain   Mont 

Wellington  Colliery  Co.,  Vancouver  Is-  1 
land  new  coal       .  .                                   J 

De  Soto   111 

Buckeve  Coal  and  Railroad  Co.,  Nelson-  1 
ville'  Ohio    J 

Roslyn   Wash  

Red  Lodge,  Mont.  
Reserve  mine   Stein  washer  .  .  .  ."  

Caledonia  mine,  Stein  washer  

Dominion  mine   Stein  washer 

Coke  from  coal    Stein  washer 

Alleghany  coal   Stein  washer 

Although  the  ash  in  this  coking  coal  is  still  high,  as  compared 
with  some  eastern  coals,  the  coke  made  from  it  has  to  compete 
with  coal  on  which  a  high  freight  rate  is  paid,  and  it  can  therefore 
be  sold  at  a  good  profit  in  spite  of  the  fact  that  36  per  cent,  of  the 
coal  mined  must  be  rejected  as  refuse. 

Mr.  J.  V.  Schaefer  says:  "The  loss  of  coal  in  the  process  was 
not  over  J  per  cent.,  and  taking  into  consideration  the  great  quan- 
tity of  matter  that  had  to  be  removed,  I  think  these  results  are 
remarkable,  and,  so  far  as  I  know,  have  never  been  surpassed." 

The  Stewart  Coal  Washer. — The  Stewart  type  of  coal  washery 
had  its  origin  in  the  desire  of  Mr.  E.  A.  Stewart,  the  patentee,  to 
design  a  plant  that  should  be  simple  in  its  arrangement  and 


114  TREATISE  ON  COKE 

operation,  effective  in  its  work,  and  at  the  same  time  have  a  large 
capacity.  The  jig  principle  was  decided  on  as  the  only  device  that 
could  be  depended  on  at  all  times  and  under  all  circumstances  to 
give  economical  results:  Instead  of  using  a  large  number  of  small 
jigs  placed  at  the  top  of  the  building,  Mr.  Stewart  adopted  the  idea 
of  using  a  few  large  jigs  placed  on  the  ground.  Instead  of  sepa- 
rating the  coal  into  many  sizes  before  washing,  and  keeping  these 
sizes  separate  throughout  the  process,  a  system  that  necessitated 
the  use  of  a  multiplicity  of  elevators  and  conveyers,  he  designed 
to  wash  the  coal  in  mixed  sizes  and  separate  afterwards,  if  desired. 
By  placing  the  jigs  on  the  ground  he  not  only  obtained  solid  founda- 
tions for  his  jig  tanks,  but  he  was  enabled  to  erect  above  the  jigs 
storage  bins  for  unwashed  coal,  from  which  the  coal  could  be  fed 
direct  into  the  jigs  without  any  intermediate  handling,  in  this 
way  again  simplifying  the  process,  as  it  is  absolutely  essential  for 
the  economical  working  of  any  washing  process  to  have  a  regular 
and  continuous  feed  of  coal  to  the  machines.  When  these  machines 
are  placed  at  the  top  of  a  building  two  systems  of  elevators  are 
required — one  for  elevating  the  raw  coal  into  the  storage  bins  and 
another  for  elevating  out  of  the  storage  bins  into  the  washing 
machines. 

In  order  that  the  coal  could  be  washed  in  mixed  sizes  effectively, 
Mr.  Stewart  designed  the  jig  that  bears  his  name,  Fig.  34.  In  this 
jig,  the  downward  suction  that  always  exists  to  a  certain  extent 
in  all  eccentric-driven  jigs  is  overcome  by  a  peculiar  arrangement 
of  valves  in  the  water-supply  pipes.  Very  remarkable  results 
have  been  accomplished  with  the  use  of  this  jig.  Its  first  marked 
success  was  achieved  in  Southern  Illinois.  From  there,  Mr. 
Stewart  moved  to  Birmingham,  Alabama,  where  the  Stewart 
washer  very  soon  demonstrated  its  superiority  in  washing  the 
Alabama  coals. 

In  Fig.  34,  a  is  the  unwashed-coal  storage  bin,  of  any  size  that 
may  be  desired,  holding  the  coal  of  all  sizes,  as  the  coal  is  not 
screened  or  sized  prior  to  washing,  b  is  a  sliding  cast-iron  gate, 
operated  by  rope  or  lever,  that  admits  the  coal  from  a  through  c 
into  d.  c  is  a  sheet-iron  housing  fastened  to  the  jig  box  d  and 
extending  into  the  box.  This  is  to  force  all  coal  going  through  c 
under  the  water-line,  so  as  to  prevent  any  fine  dust  from  floating  on 
top  of  the  water  and  passing  out  over  the  end  of  the  jig  without  its 
having  become  subjected  to  the  action  of  the  water,  c?  is  a  jig  box, 
about  5  feet  X  7  feet,  that  is  fitted  into  the  jig  tank  e  by  metal 
plates  on  the  four  sides  of  jig  tank  and  on  jig.  This  jig  box  has  a 
reciprocating  movement  and  is  worked  by  double  eccentrics  /  and  g 
keyed  to  shafting,  lying  parallel  and  geared  into  each  other  to  run 
at  the  same  speed,  The  jig  box  is  hung  from  /,  g  by  eight  rods  h. 
The  coal  after  passing  through  c  is  at  once  immersed  and  goes 
through  a  complete  disturbance  from  eight  to  ten  times  before  it 
reaches  the  point  of  discharge  for  the  coal  /  and  for  the  slate  k. 


TREATISE  ON  COKE 


115 


The  box  has,  in  the  bottom,  perforated  plates  that  slope  to  the  front 
end  where  there  is  a  sliding  gate  /.  The  capacity  of  the  jig  is  20  to 
40  tons  of  coal  per  hour.  The  jig  tank  e  is  built  in  size  to  suit  the 
jig  box  so  as  to  allow  it  to  swing  free.  The  tank  is  bushed  in  on 
four  sides  with  iron  plates  to  fit  squarely  against  the  same  character 
of  plates  on  the  jig  box,  giving  the  result  of  a  practically  tight 
joint,  but  at  the  same  time  giving  the  jig  sufficient  play  so  that  it 
can  be  moved  up  and  down  by  the  eccentrics  /  and  g  hung  on  the 
two  pieces  of  shafting  just  over  the  jig.  As  the  jig  box  goes  down, 
the  water  is  forced  through  the  perforations  in  the  plates  with 


FIG.  34.     STEWART  JIG 

sufficient  force  to  carry  the  coal  of  a  certain  specific  gravity  up 
and  over  the  lower  end  of  the  jig,  the  water  being  sluiced  through 
an  open  trough  to  the  settling  tank,  or  basin,  o\  the  speed  of  the  jig 
depends  entirely  on  the  specific  gravity  of  the  coal  that  is  being 
worked. 

The  slate  gate,  or  refuse  discharge,  /  is  raised  and  lowered 
at  will-  by  the  lever  m.  The  opening  at  k  is  adequate  to  pass  a 
4-inch  cube,  and  is  the  entire  width  of  the  jig;  the  lever  m  is 
fitted  to  a  radius  of  a  half  circle  with  slot  to  accommodate  the  open- 
ing and  shutting  of  the  gate  /,  and  is  fitted  with  handscrew  so  as 
to  enable  the  setting  of  this  gate  at  any  height.  The  operator  of 
the  jig,  after  becoming  familiar  with  his  coal  and  the  amount  of 

6 


116 


TREATISE  ON  COKE 


I  J 


_ 


Carter: 
Ash, 
30  Per  Cent. 
Sulphur, 
06  Per  Cent. 


, 
0.35  Per  Cen 
Sulphur, 
.433  Per  Cen 


iCO  O 
0005  05 


10  co  co 

CO  l>iO 


CO  TP  iO 

ioc    o 


»o  cc  10 

00  00  00 


iO"*  00 
<M        CO 


CO  00 

co 


r->  CO  t> 


_„  Ol  OS 
"*  OS  O 

OS  Oi  OS 


CO  CO 


T-lOS    t> 

OS  OS  OS 


000 

CO  CO  CO 


,-1  OS-tf 

O5  OS  t^ 


'O(M  OS 


<N<N  CO 

—i  1C  00 


impurities  it  carries  to  the  ton,  very 
readily  learns  about  the  distance  to 
leave  his  gate  open,  necessarily 
making  the  jig  as  near  absolutely 
automatic  as  any  jigging  process 
that  has  ever  been  developed. 

The  coal,  after  having  been  sepa- 
rated from  its  impurities,  passes  over 
the  top  of  the  jig  box  d  and  out  to  /, 
into  what  is  termed  the  settling 
basin  n,  where  it  is  allowed  to  set- 
tle to  the  bottom,  there  being 
very  little  disturbance  of  the  water 
in  n ;  thence  it  is  delivered  by  a  per- 
forated bucket  elevator  to  any  point 
desired. 

The  next  important  feature  is 
the  water  circulation,  the  water  being 
used  over  and  over  again.  The  only 
fresh  water  required  is  the  water  that 
is  actually  consumed  •  or  absorbed 
by  the  coal  in  the  process  of  washing. 
The  water  from  the  basin  n,  which 
overflows  from  the  top  into  a  well 
is  carried  by  any  means  desired — 
commonly  a  centrifugal  pump  on 
account  of  capacity  and  low  duty— 
into  what  is  termed  the  supply  tank 
o,  thence  through  the  opening  p  into 
tank  e  to  valve  q..  As  the  jig  box  d 
moves  up,  the  valve  being  a  cast- 
iron  swinging  check,  admits  the 
water  through  p  into  e  and  fills 
the  vacancy  caused  by  the  upward 
motion  of  d.  On  the  downward 
motion  of  the  box  d,  the  valve  q 
closes  and  the  water  is  forced 
through  the  perforated  bottom  of 
the  jig  box  d  and  the  same  process  is 
gone  over  and  over  as  has  been  cited. 
.  The  gate  in  front  of  the  jig  box 
is  left  open  at  a  certain  point,  which 
is  governed  by  the  amount  of  slate 
and  impurities  to  the  tonnage  of  coal 
being  washed.  The  down  motion  of 
the  jig  loosens  the  slate  bed  in  the 
bottom  and  works  it  toward  the 
front,  or  discharge,  side,  where  it  is 


TREATISE  ON  COKE 


117 


118  TREATISE  ON  COKE 

discharged  into  the  jig  tank  e  under  the  jig  box  and  is  carried 
by  a  chute  or  hopper  to  a  point  where  it  is  taken  up  by  the 
refuse  elevator  and  carried  out.  The  peculiar  arrangement  of 
this  jig  box  with  the  perforated  bottom  fitted  into  the  tank 
gives  a  very  sensitive  arrangement  with  which  the  jig  distin- 
guishes the  difference  between  materials  of  a  very  close  specific 
gravity;  for  instance,  in  one  case  where  the  coal  varies  in  specific 
gravity  from  1.29  to  1.37,  the  bony  coal  from  1.38  to  1.56, 
the  shale  from  1.40  to  2.04  and  the  slate  from  1.70  to  3.40,  an 
average  from  forty-nine  samples  of  run-of-mine  coal  shows  the 
coal  82.6  per  cent.,  bone  coal,  11.4  per  cent.;  shale,  4.5  per  cent.; 
slate,  1.5  per  cent.  The  following  is  the  result  of  eleven  samples 
taken  from  the  washed  product:  Coal,  92.9  per  cent.;  bone, 
5.3  per  cent.;  shale,  1.8  per  cent.  The  refuse  or  tailings  show 
coal  3.8  per  cent.;  bone,  18.2  per  cent.;  slate  and  shale, 
78.9  per  cent.  In  another  case  where  there  is  considerable 
fireclay  to  contend  with,  mixtures  of  coals  from  three  different 
places  were  washed.  The  results  of  these  washings  are  given  in 
the  table  on  page  116. 

Fig.  35  shows. a  section  and  plan,  and  Fig.  36,  a  photograph  of 
a  Stewart  washery  of  one  jig;  for  convenience  the  elevators  are 
shown  in  a  straight  line.  Although  the  washer  appears  very  rigid, 
on  the  contrary  it  is  a  very  flexible  machine,  and  can  be  made  to 
suit  almost  any  surroundings  on  account  of  the  fact  that  the  dry- 
coal  elevator  can  be  located  on  any  one  of  three  sides  of  the  washer. 
The  same  conditions  apply  to  the  washed-coal  elevator ;  it  also 
can  be  located  on  any  one  of  three  sides.  The  part  of  the  washer 
designated  as  the  settling  tank  can  be  removed  to  any  point  where 
it  can  be  located  far  enough  below  the  level  of  the  jig  so  that  the 
water  may  carry  the  coal  to  it,  but  for  convenience  sake  it  is 
located  very  close  to  the  jig  tank. 

The  illustrations  show  the  washer  located  on  approximately 
level  ground.  The  coal  if  screened,  or  if  using  run-of-mine,  is 
delivered  at  a  point  where  the  unwashed-coal  elevator  will  carry 
it  up  and  deliver  it  into  the  unwashed-coal  bin;  thence,  through 
openings  over  the  jig  box,  it  is  allowed  to  empty  into  the  jig  box 
as  freely  as  is  desired. 

The  Stewart  system  of  coal  washing  does  not  require  that  the 
coal  be  sized  prior  to  the  washing,  and  there  are  quite  a  number 
of  cases  through  Illinois  where  it  is  being  used  very  advantageously 
for  washing  coal  for  fuel  purposes,  the  coal  being  sized  after  having 
been  washed  to  take  care  of  the  fine  dust  and  breaking  of  nut  and 
pea  coal,  which  necessarily  goes  on  during  the  process  of  washing. 
Under  those  circumstances  it  is  possible  still  to  maintain  the  service 
of  a  general  loss  of  less  than  5  per  cent,  of  free  coal  in  the  process 
of  washing.  The  power  required  for  operating  the  Stewart  washer 
is  approximately  10  horsepower  per  jig.  Where  there  is  any 
screening  or  extra  conveying  machinery  attached  to  the  washer 


TREATISE  ON  COKE 


119 


the  necessary  horsepower  required  must  be  added  to  the  power  unit. 
The  amount  of  labor  required  to  attend  to  the  washer  is,  in  case  of 
more  than  a  two-jig  washer,  two  men  only,  requiring  the  ordinary 
skill  of  an  engineer  around  a  mine.  One  man  on  the  platform  of 


the  washer  can  attend  to  a  five-jig  washer,  washing  1,800  tons  per 
day  of  10  hours,  thee  ngineer  looking  after  the  engine  and  oiling  up 
the  other  machinery;  the  power  required  is  about  100  horsepower. 
The  cost  of  construction  is  a  matter  hard  to  determine,  as  it 
depends  entirely  on  the  surroundings  and  the  length  and  capacity 


120 


TREATISE  ON  COKE 


of  the  elevators  and  the  additional  machinery  required  to  dispose 
of  the  coal. 

This  system  has  become  quite  popular  throughout  the  Southern 
States,  and  the  cost  of  this  washer  is  about  $20,000. 

The  following  is  a  report  of  the  results  obtained  with  a  Stewart 
washer  at  the  Sayreton  mines  of  the  Republic  Iron  and  Steel 
Company,  made  by  the  chemist  of  the  company,  Mr.  David  Hancock: 

"Our  run-of-mine  coal,  as  shown  by  the  average  of  forty-nine 
samples  taken  in  the  mine,  is  made  up  as  follows: 


Coal 

Bone  coal . . 


PER  CENT. 
, .      82.6 
11.4 


Shale 

Slate  from  partings , 


PER  CENT. 
.  .      4.5 
1.5 


"The  average  specific  gravity  of  these  portions  I  give  below, 
showing  also  the  extent  of  variations  in  parenthesis: 

Coal 1.33  Specific  gravity  (1.29  to  1.37) 

Bone 1 . 45  Specific  gravity  ( 1 . 38  to  1 . 56) 

Shale : 1 .60  Specific  gravity  (1 .40  to  2.04) 

Slate 1 . 95  Specific  gravity  (1 . 70  to  3.40) 

"The  next  table  shows  the  results  of  10  day's  washing  and  is 
the  average  of  eleven  samples: 


WASHED  PRODUCT  PER  CENT. 

Coal 87.9 

Bone 10.3 

Shale 1.8 

Slate..  .0 


TAILINGS  .     PER  CENT. 

Coal 3.8 

Bone 18.2 

Slate  and  Shale 78.9 


"The  work  is  even  better  than  here  shown  for  the  reason  that 
it  is  the  lighter  varieties  of  bone  and  shale  that  remain  in  washed 
coal  and  the  heavier  varieties  that  go  to  the  slate  dump.  This 
point  is  well  shown  by  the  following  analysis: 

PER  CENT. 
WASHED  PRODUCT  OF  ASH 

Coal 7.50 

Bone 18.00 

Shale 33.40 


PER  CENT. 
TAILINGS  OF  ASH 

Coal 11.90 

Bone 27.90 

Shale..  .    55.00 


"I  give  finally  two  representative  analyses  of  our  coke,  one 
before  the  washer  was  installed  and  one  showing  the  coke  as  it 
now  is: 


Unwashed 

Washed 

Volatile  

3  65  per  cent 

2  75  per  cent 

Fixed  carbon  .  .  . 

76.71  per  cent 

82  55  per  cent 

Ash  

18  85  per  cent 

Sulphur  

79  per  cent 

121 


122  TREATISE  ON  COKE 

"  I  have  inspected  hundreds  of  cars  of  Sayreton  washed  coal  and 
have  never  yet  found  a  piece  of  slate  of  higher  than  1.70  specific 
gravity,  although  Sayreton  run-of-mine  carries  an  average  of 
40  pounds  per  ton  of  heavy  slate  of  this  character." 

Very  truly  yours, 

DAVID  HANCOCK,  Chemist. 


STEIN  AND  BOERICKE  WASHERY 

Since  1895,  the  Stein  washer  has  been  built  by  the  firm  of  Stein 
&  Boericke,  Limited,  of  Primos,  Delaware  County,  Pennsylvania, 
and  during  this  time  they  have  made  many  improvements  in  its 
design.  In  order  to  give  a  clear  idea  of  the  extent  of  these 
improvements  a  description  of  one  of  the  more  modern  plants 
designed  by  this  firm  is  here  given.  We  'have  selected  for  this' 
purpose  the  1,500-ton  plant  of  the  Jamison  Coal  and  Coke  Com- 
pany, of  Greensburg,  Pennsylvania,  at  their  No.  2  works.  The 
plant,  as  it  stands,  is  practically  fireproof.  The  tipple  is  of  the 
most  modern  design,  is  constructed  entirely  of  iron  and  steel,  and 
stands  over  a  raw-coal  bin  of  similar  construction  and  having  a 
capacity  of  500  tons.  All  the  buildings  are  of  massive  brick  con- 
struction and  are  covered  with  terra-cotta  tile  roofing  supported 
by  steel  roof  trusses,  the  roof  trusses  also  being  made  heavy  enough 
to  carry  all  the  main  shafting.  The  storage  bins  for  washed  coal 
are  of  steel  lined  with  brick  made  impervious  to  water.  Fig.  37 
gives  a  general  idea  of  the  outward  appearance  of  the  plant  and 
Fig.  38  shows  a  plan  and  elevation.  The  washing  plant  has  a 
capacity  of  1,500  tons  of  raw  coal  in  10  hours  and  is  designed  for 
handling  either  slack  coal  or  run-of-mine,  but  as  the  tipple  has 
about  double  this  capacity,  the  washing  plant  is  supplied  mainly 
with  the  coal  passing  through  a  3-inch  bar  screen,  the  lump  coal 
thus  prepared  being  loaded  directly  into  the  cars  by  means  of  a 
chute.  The  coal  for  the  washer  passes  directly  into  the  tooth 
crushers  a,  alt  where  it  receives  its  preliminary  preparation  for  the 
washing  plant.  From  these  crushers,  the  coal  drops  directly  into 
the  raw-coal  bin,  from  which  it  is  drawn  by  means  of  an  auto- 
matic feeding  device  through  the  dampers  c,  from  which  the  coal  is 
delivered  by  conveyers  d,  d^  to  elevators  e,  el ;  all  elevators  handling 
the  dry  coal  are  mounted  on  steel  frames  to  eliminate  danger  from 
fire.  From  elevators  e,  ev  the  coal  passes  into  the  sizing  screens  /,  flt 
the  particles  too  large  for  treatment  in  the  washer  falling  directly 
into  the  special  crushers  g,  which  are  of  such  construction  as  to 
reduce  all  coal  and  also  flat  and  irregularly  shaped  slate  to  the 
desired  size  without  any  subsequent  handling.  The  coal  thus  pre- 
pared is  delivered  by  elevators  h,  h  to  the  washing  machines  il  to  ilo, 
on  which  the  clean  coal  is  separated  from  the  slate  and  pyrites  or 
other  impurities,  and  from  which  it  is  floated  to  the  draining 
elevators  j,  jlt  from  which  it  is  distributed  by  conveyers  k,  k1  into 


TlT 


I 


Bfack&mifh  Coa/J3i 
Load /no 


Tfp]p/e 


17303— in 


FIG.  38.     PLAN  AND  SECTION  OF  WASHERY  OF  JAMISOI* 


P=>/an 


73i  Section  C  fo  D  ToE 


A:,  AND  COKE  COMPANY,  GREENSBURG,  PENNSYLVANIA 


TREATISE  ON  COKE  123 

the  storage  tanks  /,  lv  The  slate  and  other  impurities  are  received 
from  all  the  jigs  by  elevator  m,  .which  delivers  the  same  to  the 
jig  n  for  rewashing,  in  order  to  recover  any  particles  of  coal  that 
would  otherwise  be  lost  with  the  slate.  The  final  slate  passes  into 
the  settling  tank  o  and  thence  by  means  of  an  elevator  p  to  a  slate 
bin  q,  from  which  it  is  carried  away  on  cars.  There  is  also  pro- 
vision made  for  diverting  such  washed  coal  from  the  washing  plant 
as  is  suitable  for  blacksmith  purposes,  to  the  blacksmith-coal  bin  t, 
from  which  it  may  be  loaded  into  cars.  Each  of  the  washed-coal 
storage  tanks  /,  l^  has  a  capacity  of  one  day's  run  of  washed  coal 
and  is  provided  with  drainage  canals  in  the  foundations;  the  coal 
thus  properly  drained  is  taken  as  desired  through  dampers  u 
by  conveyers  v  and  elevators  w,  wl  to  the  bin  x  from  which  the  lar- 
ries  carrying  the  coal  to  the  coke  ovens  are  charged.  The  water 
from  the  entire  plant  is  gathered  in  the  settling  tanks  y,  y^  and 
the  clarified  water  is  sent  to  the  centrifugal  pumps  z^  z2,  z3  to  be 
again  circulated  through  the  plant.  The  settlings  in  y,  y1  are 
removed  by  the  conveyers  y2,  y3. 

The  machinery  used  for  the  preliminary  crushing  is  driven  by 
a  separate  engine,  not  indicated  on  the  sketch,  thus  permitting 
the  mine  and  washer  to  run  independently  of  each  other.  The 
machinery  delivering  the  washed  coal  from  the  storage  tanks  to 
the  larries  is  also  run  by  a  separate  engine,  enabling  the  larries  to 
be  charged  at  any  time  irrespective  of  the  operation  of  the  mine 
or  washer.  All  the  machinery  in  the  plant  is  very  accessible  and 
has  been  kept  on  the  ground  floor,  as  also  the  storage  tanks  and 
raw-coal  bin,  which,  as  will  be  readily  understood,  is  far  more  desir- 
able than  to  have  these  parts  of  the  plant  supported  on  trestle  work 
or  in  a  high  building.  Cement  floors  are  used  throughout  all  build- 
ings, which  greatly  facilitates  the  work  of  keeping  the  plant  clean. 

Mr.  John  M.  Jamison,  president  and  treasurer,  kindly  gives 
the  following  information  as  to  the  cost  and  work  of  this  washery: 
(1)  The  cost  of  the  washer  plant  designed  to  wash  1,500  tons  of  coal 
in  10  hours  is,  in  round  figures,  $65,000.  We  might  add  in  expla- 
nation that  our  plant  was  built  at  a  time  when  high  prices  on  all 
material  as  well  as  labor  prevailed.  (2)  The  percentage  of.  impuri- 
ties removed  from  our  coal  in  washing  .is  approximately  4  per  cent. 
(3)  Our  experience  in  washing  coal  leads  us  to  the  conclusion  that 
10  cents  per  ton  of  2,000  pounds  is  a  reasonably  safe  estimate  to  put 
upon  the  cost  of  washing  coal ;  this,  of  course,  includes  all  the  waste. 


BAUM  WASHER 

The  Baum  Washer,  Fig  39,  is  one  that  washes  from  0  inch  to 
3J  inches  without  preliminary  classification.  In  its  general  con- 
struction, the  washing  machine  on  the  Baum  system  is  similar  to 
that  of  the  well-known  pulsating  washers,  with  much  larger  dimen- 
sions, but  the  essential  difference  is  that  the  pulsating  motion  is 


124 


TREATISE  ON  COKE 


obtained  by  the  action  of  a  compressed-air,  4-foot  water  gauge, 
which  acts  on  the  surface  of  the  water  in  compartment  a,  in  such 


a  manner  that  the  movement  is  more  elastic,  but  nevertheless 
more  energetic,  than  that  obtained  by  a  piston.  The  pulsa- 
ting motion  in  the  front  compartment  of  the  washing  machine  is 


TREATISE  ON  COKE  125 

quicker  in  the  upward  than  in  the  downward  movement.  This  is 
effected  by  a  constant  inlet  of  water  into  the  compartment  a  at  b 
and  c.  The  pulsating  motion  combined  with  the  movement  of 
the  water  running  through  the  washer  is  such  that  the  coal  when 
passing  into  the  front  compartment  of  the  washing  machine  on 
the  top  of  the  sieve  d,  df  and  going  from  e  toward  /  is  classified 
in  layers  according  to  specific  gravity,  the  heavier  particles  sink- 
ing to  the  bottom.  The  lower  layer,  composed  of  dirt  and  shale,  is 
mechanically  taken  out  at  d  and  df  through  apertures,  the  height 
of  which  is  regulated  by  levers  g.  After  having  passed  through 
these  apertures,  the  shale  has  to  pass  over  a  dam,  the  height  of 
which  is  regulated  by  means  of  levers  h.  Having  passed  through 
the  apertures  d  and  dr  (see  the  arrows  on  the  drawing),  the  dirt 
falls  to  the  bottom  of  the  washing  machine  through  the  openings  i 
and  i' .  From  there  it  is  taken  by  two  Archimedean  screws  /  and 
an  elevator  k  with  perforated  buckets  to  allow  the  water  to  run  off. 

The  admission  and  exhaust  of  the  compressed  air  are  regulated 
by  sliding  valves  /  actuated  by  the  eccentrics  m.  These  valves  are 
situated  between  the  pipe  n,  conveying  the  compressed  air,  and  the 
compartment  a. 

The  coal  is  introduced,  by  means  of  a  current  of  water,  into  the 
front  compartment  of  the  washing  machine  at  e.  The  water  neces- 
sary for  the  washing  process  is  clarified  and  carried  by  the  pipe  o 
that  introduces  it  at  b  and  c. 

Classifying  Drum. — The  exit  of  the  washing  water  and  of  the 
washed  coal  is  effected  at  /  through  a  trough  that  leads  the  whole 
to  a  classifying  drum  of  large  diameter,  and  with  superimposed 
sieves  where  the  screening  is  facilitated  by  a  current  of  water  that 
forces  the  coal  through  the  holes  of  the  different  sieves  of  the 
drum;  this  peculiarity  explains  the  good  results  obtained  by  this 
apparatus.  The  drum  classifies  into  as  many  sizes  as  may  be 
desired.  Each  size  of  coal  is  then  led  through  troughs  to  the 
bunkers  for  loading  into  wagons,  after  having  received  a  quick 
rinsing  with  fresh  water  and  a  passage  over  metallic  gauze,  which 
allows  the  water  to  run  off. 

Rewashing  of  Fine  Coal. — The  fine  coal  under,  say,  £  inch  is 
taken  with  the  washing  water  underneath  the  classifying  drum  by 
a  centrifugal  pump  that  sends  it  to  a  washing  machine  similar  to 
the  one  described  above,  where  it  is  washed  again  before  being  sent 
to  the  draining  conveyer. 

Separation  of  Intergrown  Coal. — If  the  quantity  of  coal  contained 
in  the  intergrown  coal  and  dirt  is  only  insignificant,  the  intergrown 
coal  is  allowed  to  go  away  with  the  dirt.  If,  however,  the  quantity 
is  important,  the  intergrown  coal  is  separated  from  the  dirt,  in 
which  case  the  coal,  after  having  passed  through  the  first  washing 
machine,  is  sent  to  a  second  washing  machine  similar  to  the  first, 
in  which  the  lower  layer  will  be  formed  by  the  intergrown  coal, 
which  is  recovered  as  described  above. 


TREATISE  ON  COKE  127 

Separation  of  the  Dirt  Out  of  the  Intergrown  Coal. — It  is  some- 
times advisable  to  crush  the  intergrown  coal  in  order  to  effectively 
separate  the  dirt  from  it ;  in  that  case  the  crushed  intergrown  coal 
is  mixed  with  the  fine  coal  before  it  enters  into  the  last  washing 
machine. 

Draining  Plant. — The  draining  plant,  Fig.  40,  is  able  to  reduce 
the  added  moisture  in  the  coal  to  such  reasonable  percentage  as 
may  be  desired;  at  the  same  time,  it  clarifies  the  washing  water 
by  extracting  a  great  part  of  the  slurry  by  filtration  through  a 
constantly  renewed  layer  of  fine  coal.  This  draining  plant  consists 
of  an  extremely  strong  conveyer,  carrying  about  2  tons  of  coal  per 
yard.  The  conveyer  is  made  with  perforated  plates  a,  hinged 
one  to  the  other,  and  carrying  on  the  middle  a  double  vertical 
partition  b  of  perforated  sheets,  strengthened  with  angle  irons,  and 
slightly  separated  from  each  other  to  allow  the  water  to  run  between 
them;  the  two  upright  sides  c  and  d  are  also  perforated.  The  con- 
veyer thus  presents  an  aspect%of  a  series  of  boxes  hinged  one  to  the 
other  in  the  middle  of  the  bottom. 

The  washing  water  comes  with  the  fine  coal  on  especially 
arranged  swinging  sieves  of  metallic  gauze,  which,  as  indicated  in 
Fig.  40,  allow  the  water,  the  slurry,  and  the  very  fine  coal  to  pass 
through,  while  the  coarser  coal  slides  down  to  the  conveyer  at  e. 
The  finer  coal  and  the  slurry,  separated  as  just  mentioned,  then 
fall  on  top  of  the  coarser  coal  from  /  to  g.  The  coal  is  now  in  the 
best  condition  for  draining. 

As  the  conveyer  moves,  it  passes  over  the  supporting  rollers  h, 
the  distances  and  the  difference  of  height  between  which  are  calcu- 
lated so  as  to  let  the  conveyer  bend  under  the  load  of  coal  between 
one  roller  and  the  other.  The  effect  of  this  sagging  of  the  conveyer 
is  to  press  the  coal  between  the  vertical  partitions  b  when  it  arrives 
between  the  rollers,  or  above  the  lower  rollers,  and  to  open  these 
partitions  one  from  the  other  as  it  arrives  above  the  higher  rollers. 
The  coal  is  in  this  way  submitted  to  a  process  of  pressure  and 
expansion  that  compels  the  separation  of  the  water  from  the  coal. 
This  water,  in  passing  through  the  layer  of  coarser  coal  at  the 
bottom  of  the  boxes,  leaves  a  great  part  of  the  slurry  on  the  drain- 
ing conveyer.  It  is  afterwards  recovered  at  i,  and  sent  through 
especially  designed  settling  tanks  insuring  its  thorough  clarification. 
After  clarification,  the  water  is  used  over  again  in  the  washer. 

Regulation  of  Moisture. — The  percentage  of  water  left  in  the 
coal  may  be  regulated  by  the  speed  of  the  conveyer,  which  has  a 
length  of  about  22  yards,  and  generally  a  speed  of  about  8  inches 
per  minute.  If  it  is  run  more  rapidly,  the  percentage  of  water  is 
larger,  the  coal  having  thus  less  time  for  draining,  and  vice  versa. 

Settling  Tanks. — The  settling  tanks,  Fig.  41,  are  established  in 
such  a  manner  that  the  slurry  still  contained  in  the  washing  water, 
after  its  passage  through  the  draining  conveyer,  is  automatically 
and  continuously  recovered.  In  the  latest  plants  there  is  only  one 


128 


TREATISE  ON  COKE 


settling  tank  of  large  diameter  (33  feet  diameter  and  39  feet  deep) , 
which  is  constructed  in  iron  and  supported  by  a  brick  tower  out- 
side the  washer  building.  In  some  plants,  the  settling  tanks  are 
placed  inside  the  washer  building  on  the  same  floor  as  the  coal 
hopper.  Their  object  is  always  the  same,  facilitating  the  deposit 

of  the  slurry  by  a  sudden  stop- 
page in  the  speed  of  the  current 
of  water. 

The  tank  is  the  shape  of  a 
cone,  with  the  point  downwards. 
The  water  containing  the  slurry 
is  pumped  through  the  pipe  a, 
Fig.  41,  at  the  point  b.  It  meets 
the  shield  c  and  is  then  compelled 
to  cross  the  tank  from  the  cen- 
ter to  the  circumference,  and 
consequently  with  a  speed  de- 
creasing in  geometrical  progres- 
sion, before  it  falls  into  the 
gutter  d  that  surrounds  the  tank. 
The  water  is  thus  recovered  in 
a  clarified  state  in  this  gutter, 
and  is  taken  away  by  the  pipe  e 
to  the  washer.  The  slurry  fall- 

Fio.  41.     SETTLING  TANK  ™%  tO  the  bottom  of  the  tank  is 

continuously    extracted    in    the 

form  of  a  liquid  mud  through  the  pipe  g,  which  takes  it  again  to 
the  draining  plant  if  it  is  clean,  and  where  it  remains  with  the  fine 
eoal;  or,  if  it  is  too  dirty,  it  is  sent  into  tanks  of  small  area  out- 
side the  washer,  where  it  is  collected  and  used  when  and  where 
the  colliery  finds  it  advantageous. 

A  Baum  Washing  Plant. — The  coal  washer,  Fig.  42,  erected  at 
Gladbeck,  Westphalia,  may  be  considered  as  a  standard  washer  on 
the  Baum  system.  The  coal  is  brought  from  the  screening  plant  a 
through  jigging  screens  b  passing  everything  under  3  inches  into 
the  hopper  c.  It  is  then  lifted  by  an  elevator  d  to  the  top  of 
the  washer  building.  It  receives  at  e  a  current  of  water  that 
pushes  it  into  the  first  washing  machine  /.  The  shale  falls  to  the 
bottom  of  this  washing  machine  and  is  caught  by  an  elevator  with 
perforated  buckets  g,  and  dropped  along  chutes  into  the  hopper  h. 
The  washed  coal  is  then  conducted  to  the  classifying  drum  it 
which  classifies  into  five,  or  as  many  sizes  as  may  be  desired.  Each 
size  is  delivered  into  hoppers  /  by  means  of  chutes  k  and  spirals, 
which  take  the  nuts  without  breakage  up  to  the  loading  hoppers, 
each  having  a  capacity  of  50  tons. 

The  fine  coal  from  0  inch  to  £  inch  falls  with  the  washing  water 
into  a  centrifugal  pump  /,  which  lifts  it  into  a  second  washing 


'^\        *         ?      '.  •        f 


17303— in 


FIG.  42.     WASHING  PLANT  ON  BAU 


AT  GLADBECK,  WESTPHALIA 


TREATISE  ON  COKE  129 

machine  m,  where  it  is  again  washed  and  the  last  traces  of  fine  dirt 
extracted.  The  dirt  is  lifted  by  an  elevator  with  perforated 
buckets  n  and  sent  down  to  the  hopper  h.  The  fine  coal  leaving 
the  second  washing  machine  is  carried  by  the  washing  water  to 
the  draining  band  o,  which  delivers  it  with  the  desired  percentage 
of  moisture  into  the  hopper  p,  which  has  a  capacity  of  200  tons, 
where  it  is  spread  by  means  of  Archimedean  screws.  In  some 
plants  this  fine  coal  is  crushed  at  the  end  of  the  draining  band  by 
a  disintegrator  situated  above  the  bunkers  p. 

The  washing  water  undergoes  a  second  clarification  in  the 
settling  tanks  q  in  the  washer  building.  The  slurry  continuously 
extracted  through  the  bottom  apertures  r  is  conducted  in  the 
shape  of  a  liquid  mud  to  the  centrifugal  pump  s,  which  pumps  it 
again  on  to  the  draining  band  at  t.  The  clarified  water  is  pumped 
through  a  centrifugal  pump  and  sent  back  to  the  washer.  The 
settling  tanks  can  be  replaced  by  the  one  previously  described  and 
placed  outside  the  washer  building.  Such  an  arrangement  gives 
more  room  for  the  fine-coal  bunkers.  The  compressed  air  is  pro- 
vided by  the  rotary  blower  v. 

The  washed  sized  coal  is  loaded  directly  into  the  railway  wagons  by 
the  chutes  w,  provided  at  %  with  rinsing  apparatus,  and  the  washed 
fine  coal  is  either  loaded  directly  into  the  railway  wagons  or  into  the 
larries  y,  situated  at  the  level  of  the  top  of  the  coke  ovens.  All 
the  motors  of  this  washer  are  electric,  having  a  total  power  of  140 
horsepower.  This  washer  deals  with  100  tons  per  hour  of  raw  coal. 

Washer  for  Fine  Coal. — In  cases  where  it  is  only  required  to 
wash  fine  coal  without  sizing,  the  arrangement  of  the  plant  is  as 
shown  in  Fig.  43.  The  coal  is  brought  to  point  a  either  by  means 
of  an  elevator  or  by  a  creeper  coming  direct  from  the  screening 
plant.  It  meets  at  a  a  current  of  water  that  pushes  it  into  the 
washing  machine  6,  suitably  constructed  to  wash  fine  coal  only, 
say,  under  J  inch  or  f  inch. 

The  dirt  falls,  as  explained  previously,  to  the  bottom  of  the 
washing  machine,  where  it  is  taken  by  an  elevator  with  perforated 
buckets  c  and  sent  from  there  into  the  dirt  wagons  d  standing 
alongside  the  building.  The  washed  coal  is  then  carried  along 
with  the  water  on  the  draining  band  e  and  delivered  dry  at  /.  At 
this  point,  the  coal  may  either  be  loaded  directly  into  the  railway 
wagons  or  may  be  delivered  by  the  elevator  g  shown  in  dotted  lines 
on  the  drawing,  which  takes  it  through  the  disintegrator  and,  by 
means  of  scrapers  h,  into  the  coal  bunkers. 

The  water,  having  undergone  a  first  clarification  through  the 
draining  band,  is  compelled  to  cross  the  settling  tanks  i  through 
their  full  length,  where  it  drops  the  slurry,  which  is  continuously 
pumped  back  on  to  the  draining  band  by  a  centrifugal  pump  /. 
The  clarified  water  is  pumped  at  point  k  by  the  centrifugal  pump  / 
and  sent  back  to  the  washer. 


130 


TREATISE  ON  COKE 


The  compressed  air  is  provided  by  the  blower  m. 

The  power  for  driving  may  be  either  steam  or  electricity,  and 
varies  from  40  to  60  horsepower  according  to  the  size  of  the  plant. 
The  engine  or  motor  is  in  the  engine  room  n,  together  with  the 


v^rf  /  //    £?, 
yx_/__y/ 

I r • 

—  _       _«~^_  _j^-_        -r»^_ 


FIG.  43 

different  pumps.  The  building,  partly  supported  by  cast-iron 
pillars,  is  of  brickwork  for  the  first  story,  and  above  the  first  story, 
of  iron  filled  in  with  brickwork. 

This  very  efficient  washing  plant  is  made  in  three  different 
sizes,  to  treat  from  20  to  40  tons  of  coal  per  hour,  and  can  be  erected 
and  started  to  work  within  six  months.  Above  that  capacity 
some  alterations  are  made  to  the  plant. 


CHAPTER  IV 


HISTORY  AND  DEVELOPMENT  OF  THE  COKE  INDUSTRY 

History. — Authorities  are  not  in  harmony  as  to  the  time  of  the 
beginning  of  coke  manufacture  in  England.  In  1735,  Darby  is 
reported  as  using  coke  successfully  at  Coalbrookdale,  in  Shrop- 
shire; but  little  was  accomplished,  however,  until  1750,  when  its 
use  became  extended  as  a  blast-furnace  fuel.  Evidently  the  same 
economic  conditions  that  subsequently  expanded  the  use  of  coke 
in  the  United  States  of  America  had  their  earlier  force  in  England, 
for  the  scarcity  of  wood  for  making  charcoal  and  its  increasing 
cost  forced  iron  manufacturers  to  search  for  and  use  a  less  expen- 
sive fuel.  The  late  Mr.  Joseph  D.  Weeks  has  called  attention 
to  the  fact  that  from  the  abundance  of  wood  for  making  charcoal 
in  the  United  States  and  the  encouragement  given  to  the  exporta- 
tion of  charcoal  metal  to  England,  it  is  quite  improbable  that 
much,  if  any,  coke  was  manufactured  prior  to  the  Revolution. 

In  May,  1813,  an  advertisement  appeared  in  the  Pittsburg 
Mercury,  indicating  that  John  Beal,  an  English  emigrant,  who 
possessed  the  knowledge  "of  converting  stone  coal  into  coak," 
would,  under  certain  conditions,  communicate  the  same  "to  pro- 
prietors of  blast  furnaces."  It  is  not  on  record  whether  this  offer 
led  to  the  introduction  of  the  manufacture  of  coke  in  America. 

Shortly  after  this,  however,  in  1816-17,  Col.  Isaac  Meason 
built  the  first  rolling  mill,  west  of  the  Alleghany  Mountains,  to 
puddle  iron  and  roll  it  into  bars,  in  Fayette  County,  Pennsylvania; 
this  mill  went  into  operation  in  September,  1817.  Shortly  after 
this  time,  general  attention  was  directed  to  the  rapid  disappear- 
ance of  the  forests  of  Pennsylvania,  accompanied  by  the  discovery 
of  large  deposits  of  coal,  all  pointing  to  the  necessity  of  its  manu- 
facture into  coke  for  use  in  the  growing  iron  industry. 

In  1825,  the  acting  committee  of  the  Pennsylvania  Society  for 
the  Promotion  of  Internal  Improvements  sent  Mr.  William  Strick- 
land to  England,  as  their  agent,  to  study  various  subjects  relating 
to  internal  improvements,  and  to  investigate  the  methods  employed 
in  the  manufacture  of  iron.  His  letter  of  instruction  was  as  follows : 

"Attempts  of  the  most  costly  kind  have  been  made  to  use  the 
coal  of  the  western  part  of  our  state  in  the  production  of  iron. 
Furnaces  have  been  constructed  according  to  the  plan  said  to  be 
adopted  in  Wales  and  elsewhere;  persons  claiming  experience  in 
the  business  have  been  employed,  but  all  has  been  unsuccessful. 

7  131 


132  TREATISE  ON  COKE 

In  large  sections  of  our  state,  ore  of  the  finest  quality,  coal  in  the 
utmost  abundance,  limestone  of  the  best  kind,  lie  in  immediate 
contiguity,  and  water-power  is  within  the  shortest  distance  of 
these  mines  of  future  wealth. 

"The  prices  which  are  obtained  for  iron  on  the  western  waters 
are  double  those  of  England,  the  demand  is  always  greater  than 
the  supply,  and  thus  nothing  but  knowledge  of  the  art  of  using 
these  rich  possessions  is  wanted. 

"We  desire  your  attention  to  the  following  inquiries  on  the 
subject  of  the  manufacture  of  iron: 

"1.  What  is  the  most  approved  and  frequent  process  for  coking 
coal,  and  what  is  the  expense  per  ton  or  caldron? 

"2.  In  what  manner  are  the  arrangements  or  buildings,  if 
any,  constructed  for  the  coking  of  coal,  obtaining  drawings  and 
profiles  thereof? 

"3.  Are  there  different  modes  for  coking  coal ;  and  if  they  have 
any  difference  in  principle,  what  are  they? 

"4.  In  what  manner  are  the  most  approved  furnaces  for  the 
smelting  of  ore  constructed  ?  Drawings  and  sections  of  the  same  to 
accompany  the  information  that  may  be  obtained  upon  this  inquiry." 

Mr.  Strickland  reported  intelligently,  with  full  drawings,  illus- 
trating the  methods  of  coke  making  and  the  construction  of  blast 
furnaces  for  using  this  new  fuel. 

As  these  investigations  were  completed  in  1825,  it  is  inferred 
that  coke  had  been  in  use  before  this  time.  A  paragraph  in  the 
history  of  Fayette  County  refers  to  the  use  of  coke  in  the  Alleghany 
furnace  in  Blair  County  in  1811. 

Mr.  James  M.  Swank,  general  manager  of  the  American  Iron  and 
Steel  Association,  Philadelphia,  suggests  that  the  early  efforts  in  the 
use  of  coke  in  blast  furnaces  were  made  in  mixtures  with  charcoal. 

In  1835,  the  Franklin  Institute  of  Pennsylvania  offered  a  pre- 
mium of  a  gold  medal  to  "the  person  who  shall  manufacture  in 
the  United  States  the  greatest  quantity  of  iron  from  the  ore  during 
the  year,  using  no  other  fuel  than  bituminous  coal  or  coke,  the 
quantity  to  be  not  less  than  20  tons."  In  the  same  year,  Mr. 
William  Firmstone  was  successful  in  making  good  gray  forge  iron 
for  about  1  month  at  the  Mary  Anne  furnace,  in  Huntingdon 
County,  Pennsylvania,  with  coke  made  from  Broad  Top  coal. 

In  1837,  F.  H.  Oliphant  made  about  100  tons  of  coke  iron  at 
his  Fairchance  furnace,  near  Uniontown,  Fayette  County,  Penn- 
sylvania; and  in  the  same  year  coke  was  successfully  used  in  the 
Lonaconing  furnace,  Frostburg,  Maryland. 

These  early  efforts  in  the  use  of  coke  in  blast  furnaces  were  not 
very  successful.  Probably  this  came  from  the  imperfect  methods 
of  making  coke  and  the  insufficient  blast  to  the  furnace.  The 
latter  was,  perhaps,  the  most  retarding  cause  in  the  early  efforts 
in  smelting  pig  iron  with  coke.  While  these  experimental  tests  in 
the  use  of  coke  were  carried  forward  in  Pennsylvania  and  Maryland, 


TREATISE  ON  COKE 


133 


other  states  were  also  making  efforts  in  the  same  direction.  Coke 
did  not  come  into  use  rapidly.  In  1849,  Prof.  J.  P.  Lesley  failed 
to  record  a  single  coke  furnace  in  blast  in  Pennsylvania.  In  1856, 
however,  he  reported  21  furnaces  in  blast  in  Pennsylvania  and  3 
in  Maryland  using  coke. 

The  early  history  of  coke  making  in  the  Connellsville  region  is 
involved  in  some  obscurity;  but  Colonel  Meason  used  coke  at  his 
refinery  in  1819.  In  1841,  two  carpenters,  Provence  McCormick 
and  James  Campbell,  united  with  a  stone  mason,  Mr.  John  Taylor, 
in  a  coking  enterprise.  The  mason  was  to  build  the  coke  ovens  and 
the  carpenters  would  construct  the  arks  to  convey  the  coke  by 
river  to  market  at  Cincinnati.  Two  ovens  were  built  about  10  feet 
in  diameter.  The  coal  charge  was  about  80  bushels.  In  the  spring 
of  1842  enough  coke  was  made  to  load  two  boats  90  feet  long, 
about  800  bushels  each.  These  were  taken  to  Cincinnati,  but  the 
demand  was  trifling  and  the  parties,  losing  heavily  in  the  enterprise, 
became  disgusted  with  the  outlook  for  marketing  coke.  This  was 
the  beginning  of  the  manufacture  of  coke  in  the  great  Connellsville 
field,  which  now  sends  to  market  annually  over  14  millions  of  tons. 

The  growth  of  the  coke  industry  was  undoubtedly  greatly  assisted 
by  the  excellent  product  of  Connellsville,  but  the  manufacture 
struggled  along  up  to  1880  without  impressing  its  value  as  of  suffi- 
cient importance  to  give  it  a  place  in  the  statistics  of  the  products  of 
the  industries  of  the  United  States.  It  has  now  attained  a  position 
and  magnitude  of  prime  importance  in  all  metallurgical  operations. 

The  following  table  will  show  the  number  of  coke  establish- 
ments in  the  United  States,  indicating  the  growth  of  the  manu- 
facture of  coke  from  1850  to  1903. 

STATISTICS  SHOWING  DEVELOPMENT  OF  COKE  INDUSTRY 


Year 

Number  of 
Establish- 
ments 

Year 

Number  of 
Establish- 
ments 

1850 

Census  Year 

4 

1890 

December  31 

253 

1860 

Census  Year 

21 

1891 

December  31 

243 

1870 

Census  Year 

25 

1892 

December  31 

261 

1880 

Census  Year 

149 

1893 

December  31 

258 

1880 

December  31 

186 

1894 

December  31 

260 

1881 

December  31 

197 

1895 

December  31 

265 

1882 

December  31 

215 

1896 

December  31 

341 

1883 

December  31 

231 

1897 

December  31 

336 

1884 

December  31 

250 

1898 

December  31 

341 

1885 

December  31 

233 

1899 

December  31 

343 

1886 

December  31 

222 

1900 

December  31 

388 

1887 

December  31 

270 

1901 

December  31 

423 

1888 

December  31 

261 

1902 

December  31 

456 

1889 

December  31 

252 

NOTE. — The  above  and  several  following  statistical  tables  are  taken 
from  the  United  States  Geological  Survey,  Department  of  Mineral  Resources. 


134 


TREATISE  ON  COKE 


NUMBER   OF    COKE    OVENS,   BEEHIVE   AND    BY-PRODUCT,   IN   THE 

UNITED   STATES  ON    DECEMBER  31  OF   EACH  YEAR   FROM 

1880   TO    1902,  WITH  THEIR  ANNUAL  OUTPUTS 


Year 

Number  of 
Ovens 

Output 
Net  Tons 

Year 

Number  of 
Ovens 

Output 
Net  Tons 

1880 

12,372 

3,338,300 

1892 

42,002 

12,010,829 

1881 

14,119 

4,113,760 

1893 

44,201 

9,477,580 

1882 

16,356 

4,793,321 

1894 

44,772 

9,203,632 

1883 

18,304 

5,464,721 

1895 

45,565 

13,333,714 

1884 

19,557 

4,873,805 

1896 

46,944 

11,788,773 

1885 

20,116 

5,106,696 

1897 

47,668 

13,288,984 

1886 

22,597 

6,845,369 

1898 

48,383 

16,047,209 

1887 

26,001 

7,611,705 

1899 

49,603 

19,668,569 

1888 

30,059 

8,540,030 

1900 

58,484 

20,533,348 

1889* 

34,165 

10,258,022 

1901 

64,001 

21,795,883 

1890 

37,158 

11,508,021 

1902 

69,069 

25,401,730 

1891 

40,057 

10,352,688 

The  year  1880  marks  the  first  great  appreciation  of  the  value 
of  coke  for  the  manufacture  of  Bessemer  pig  iron.  It  marked  an 
era  of  rapid  uplift  in  the  values  of  coke  and  coking-coal  lands.  It  is 
well  to  note  that  the  number  of  ovens  at  the  close  of  each  year 
represents  those  in  existence,  but  it  does  not  mean  that  there  were 

RECORD  OF  BY-PRODUCT  COKE  MAKING  FROM  1893  TO  1902 


Ovens 

Year 

Production 

x  ear 

Net  Tons 

Built 

Building 

1893 

12 

12,850 

1894 

12 

60 

16,500 

1895 

72 

60 

18,521 

1896 

160 

120 

83,038 

1897 

280 

240 

261,912 

1898 

520 

500 

294,445 

1899 

1,020 

65 

906,534 

1900 

1,085 

1.096 

1,075,727 

1901 

1,165 

1,533 

1,179,900 

1902 

*1,663 

tl,346 

1:1,403,588 

*  Includes  525  Semet-Solvay,  1,067  Otto-Hoffman,  15  Schniewind,  and 
56  Newton  Chamber's  ovens;  flncludes  210  Semet-Solvay,  664  Otto-Hoff- 
man, 412  Schniewind,  and  60  Retort  Coke  Company  ovens;  JBy-product 
coke  embraced  in  general  table  of  coke  production  in  the  United  States. 

that  many  in  active  operation.  In  this  connection  it  is  interesting 
to  note  the  increase  in  the  productive  capacity  of  the  coke  ovens 
in  the  United  States.  It  is  not  possible  to  compare  the  number 
of  ovens  in  actual  operation  each  year,  and  the  averages  must  be 


TREATISE  ON  COKE 


135 


based  on  the  number  of  ovens  in  existence  at  the  close  of  each 
year.  In  1880,  the  number  of  ovens  in  existence  was  12,372  and 
the  total  coke  production  was  3,338,300  net  tons,  an  average  of 
278  tons  of  coke  per  oven.  In  1890,  the  total  number  of  ovens 
reported  was  37,158  and  the  production  of  coke  was  11,508,021  net 
tons,  an  average  of  310  tons  of  coke  per  oven.  In  1900,  the  total 
number  of  ovens  reported  was  58,484  and  the  production  was 
20,533,348  net  tons,  an  average  of  351  tons  of  coke  per  oven.  The 
number  of  ovens  in  use  in  1900  was  4.7  times  those  in  existence  in 
1880.  The  output  of  coke  in  1900  was  6.2  times. that  of  1880. 
The  increase  of  production  in  1901,  as  compared  with  the  preceding 
year,  was  1,262,535  net  tons,  or  6.15  per  cent.  Coke  production 
in  1902  overtopped  all  previous  records;  it  was  25,401,730  net  tons, 
exhibiting  an  increase  over  1901  of  3,605,847  net  tons  or  16.5  per 

RECORD  OF  BY-PRODUCT  COKE  OVENS  BY  STATES,  AT  THE 
CLOSE  OF   1900,  1901,  AND   1902 


States 

Ovens, 
December  31,  1900 

Ovens, 
December  31,  1901 

Ovens, 
December  31,  1902 

Completed 

Building 

Completed 

Building 

Completed 

Building 

Alabama  

120 
400 

30 

355 

60 
120 

120 

30 
100 
564 
50 
232 

120 

400 
30 

•     30 
.    50 
355 
60 
120 

120 

200 

45 
100 
564 

504 

240 

400 
75 
100 
30 
50 
592 
56 
120 

40 
200 

60 

574 
60 
412 

Maryland 

Massachusetts.  .  .  . 
Michigan  
New  Jersey  
New  York  . 

Ohio  .  . 

Pennsylvania.  .  .  . 
Virginia  
West  Virginia.  .  .  . 

Totals  

1,085 

1,096 

1,165 

1,533 

1,663 

1,346 

cent.  The  inability  of  railroads  to  furnish  cars  and  motive  power 
materially  reduced  this  year's  output,  increasing  the  expense  of 
production. 

The  records  of  the  number  of  by-product  coke  ovens  in  the 
above  table  are  accumulative;  the  whole  number  of  these  ovens 
completed  and  building  in  the  United  States  at  the  close  of  the 
year  1902  is  given  in  the  last  two  columns,  1,663  built  and  1,346 
building. 

By  the  term  yield  is  meant  the  percentage  of  merchantable  coke 
that  has  been  'obtained  from  the  coal  used  in  its  manufacture. 
The  table  shows  that  the  genera,!  average  for  most  of  the  years 
given  is  about  64  per  cent.,  but  in  most  instances  this  indicates 
the  value  of  the  coke  oven  used  and  the  care  afforded  the  coking 
operations.  Until  recent  years,  these  elements  in  securing  full 


136 


TREATISE  ON  COKE 


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iO 


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1C  CO  *O     00 


r    O  CD 
(M  "tf  T-H 


T-HCOO 

i-tOiO 

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t^COOO 


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II 

SI 

e    -s 


TREATISE  ON  COKE 


137 


APPROXIMATE   STATEMENT   OF   AMOUNT   OF   COAL   REQUIRED   TO 

PRODUCE   1  TON  OF  COKE  IN  EACH  YEAR  SINCE   1880, 

WITH   PERCENTAGE    OF   YIELD    (NET   TONS)* 


Year 

Tons 

Pounds 

Per  Cent. 
Yield 

Year 

Tons 

Pounds 

Per  Cent. 
Yield 

1880 

1.57 

3,140 

63.0 

1892 

1.57 

3,140 

64.0 

1881 

1.59 

3,180 

63.0 

1893 

1.57 

3,140 

63.5 

1882 

1.58 

3,160 

63.0 

1894 

1.56 

3,120 

64.0 

1883 

1.56 

3,120 

64.0 

1895 

1.56 

3,120 

64  0 

1884 

1.63 

3,260 

61.0 

1896 

1.58* 

3,170 

63.0 

1885 

1.58 

3,160 

63.0 

1897 

1.57 

3,140 

63.5 

1886 

1  56 

3,120 

64.0 

1898 

1.57 

3,140 

63.6 

1887 

1.56 

•3,120 

64.2 

1899 

1.54 

3,080 

65.1 

1888 

1.51 

3,020 

66.0 

1900 

1.57 

3,140 

63.9 

1889 

1.55 

3,100 

64  0 

1901 

1.57 

3,140 

63.9 

1890 

1.56 

3,120 

64.0 

1902 

1.56 

3,129 

64.1 

1891 

1.58 

3,100 

63.0 

*These  figures  include  both  beehive  and  by-product  coke. 

PERCENTAGE  OF  YIELD  OF  COKE  FROM  THE  SEVERAL  QUALITIES 
OF  COALS  USED  IN  ITS  MANUFACTURE  IN  EACH  STATE 
AND    TERRITORY    DURING    1896-1902 


State  or  Territory 

1896 

1897 

1898 

1899 

1900 

1901 

1902 

Alabama, 

57  5 

58  8 

59  0 

59  0 

58  9 

55  8 

60  2 

Colorado  a  
Georgia 

56.9 
49  0 

55.6 
49  3 

59.1 
61  0 

59.0 
65  2 

62.0 
52  4 

58.4 
60  7 

59.2 
63  3 

Illinois 

66  7 

43  0 

35  0\ 

Indiana 

49.0 

41  4 

44.  9J 

56.2 

57.1 

Indian  Territory  .  . 
Kansas 

40.0 
53.5 

44.3 
52  5 

46.5 
53  0 

41.0 
53  6 

48.0 

57.7 

50.0 
61.4 

44.6 
58.3 

Kentucky  .  . 

48.6 

50.0 

50  0 

53  5 

50.2 

49.0 

47.8 

Massachusetts  ..... 
Missouri  

55.9 

56.0 

49  3 

53.8 

55.3 

52.5 

55.4 

Montana.  
New  Mexico  
New  York  
Ohio  
Pennsylvania  6.  .  .  . 
Tennessee  ......... 
Texas  

53.0 
61.7 

62.7 
66.1 
56.5 

48.5 
55.6 

62.7 
66.2 
55.0 
56.3 

56.0 
55.6 

63.5 
65.7 
54.6 

51.0 
64.3 

58.8 
68.1 
55.8 

50.3 
60.3 

62.5 
66.2 
55.6 

55.4 
57.5 

66.9 
66.0 
54.6 

53.7 
56.9 

66.6 
65.9 
54.6 

Utah  
Virginia  

58.9 

61.6 

62.0 

62.2 

63.2 

64.7 

65.5 

Washington  
West  Virginia  
^Visconsin 

67.0 
61.4 
62  0 

67.0 
61.0 
59  0 

62.2 
61.2 
59.0 

59.8 
60.0 
60.8 

61.5 
60.9 
60.01 

62.7 
61.1 

58.8 
61.7 

Wyoming  

47.6 

43.7 

51.9 

48.7 

44.  7J 

71.  lc 

70.  2C 

Total  average  .  .  . 

63. 

63.5 

63.6 

65.1 

63.9 

63.7 

64.1 

0  Average,  including  Utah. 

6  Average,  including  New  York,  also  Massachusetts  for  1899. 
c  Includes    Illinois,     Indiana,    Massachusetts,    Michigan,    New   York, 
Wisconsin,  and  Wyoming. 


13cS 


TREATISE  ON  COKE 


yields  from  the  several  qualities  of  the  coals  have  not  received  the 
consideration  that  their  importance  demanded. 

Two  elements  must  be  harmonized  to  secure  the  largest  per- 
centage of  merchantable  coke  in  the  different  types  of  coke  ovens: 
(1)  properly  applied  skill;  (2)  correct  knowledge  of  the  quality  of 
the  coking  coal.  It  may  be  added  that  in  all  dry  coals  inheriting 
a  large  percentage  of  fixed  carbon,  with  a  correspondingly  low 
volume  of  hydrogenous  matter,  some  of  this  fixed  carbon  must  be 
consumed  in  the  coking  process;  while,  on  the  other  hand,  coking 
coal  with  a  large  volume  of  volatile  combustible  matter  will  require 
very  little  of  its  fixed  carbon  in  the  process  of  coking. 

The  table  on  page  137  indicates  a  slight  general  average  increase 
of  percentage  of  coke  product  during  1902  over  that  of  1901,  but 
there  is  evidently  room  for  further  increased  percentage  of  coke. 

DIAGRAM    ILLUSTRATING    THE    GROWTH    OF    THE    MANUFACTURE 

OF  COKE   IN   THE  UNITED  STATES  FROM    1880  TO 

1902,  INCLUSIVE 


/\ 


\7 


\ 


Years 


TREATISE  ON  COKE 


139 


AMOUNT  OF  COKE  PRODUCED  IN  THE  UNITED  STATES  FROM 

1880  TO  1902 


Year 

Net  Tons 

Year 

Net  Tons 

Year 

Net  Tons 

1880 

3,338,300 

1888 

8,540,030 

1896 

11,788,773 

1881 

4,113,760 

1889 

10,258,022 

1897 

13,288,984 

1882 

4,793,321 

1890 

11,508,021 

1898 

16,047,209 

1883 

5,464,721 

1891 

10,352,688 

1899 

19,668,569 

1884 

4,873,805 

1892 

12,010,829 

1900 

20,533,348 

1885 

5,106,696 

1893 

9,477,580 

1901 

21,795,883 

1886 

6,845,369 

1894 

9,203,632 

1902 

25,401,730 

1887 

7,611,705 

1895 

13,333,714 

COKE  IMPORTED  AND  ENTERED  FOR  CONSUMPTION  IN  THE  UNITED 
STATES    FROM    1869    TO    1902  (NET   TONS) 


Year 
Ending 
June  30 

Quantity 

Value 

Year 
Ending 
Dec.  31 

Quantity 

Value 

1869 

$  2,053 

1886 

28,124 

$  84,801 

1870 

6,388 

1887 

35,320 

100,312 

1871 

19,528 

1888 

•   35,210 

107,914 

1872 

9,575 

9,217 

1889 

28,608 

88,088 

1873 

1,091 

1,366 

1890 

20,808 

101,767 

1874 

634 

4,588 

1891 

50,753 

223,184 

1875 

1,046 

9,648 

1892 

27,420 

86,350 

1876 

2,065 

8,657 

1893 

37,183 

99,683 

1877 

4,068 

16,686 

1894 

32,566 

70,359 

1878 

6,616 

24,186 

1895 

29,622 

71,366 

1879 

6,035 

24,748 

1896 

43,372 

114,712 

1880 

5,047 

18,406 

1897 

34,937 

98,077 

1881 

15,210 

64,987 

1898 

46,127 

142,334 

1882 

14,924 

53,244 

1899 

31,197 

142,504 

1883 

20,634 

113,114 

1900 

115,556 

371,341 

1884 

14,483 

36,278 

1901 

72,727 

266,075 

1885 

20,876 

64,814 

1902 

140,488 

423,775 

From  the  above  it  will  be  seen  that  this  imported  coke  cost 
per  ton  as  follows:  1872,  $.962;  1880,  $3.645;  1890,  $4.8975; 
1900,  $3.215;  1902,  $3.165. 

COKE  EXPORTED  FROM  THE  UNITED  STATES  SINCE  1895 
(NET  TONS) 


Year 

Quantity 

Value 

Year 

Quantity 

Value 

1895 

.   1896 
1897 
1898 

131,368 
169,189 
173,034 
199,562 

$425,174 
553,600 
546,066 
600,931 

1899 

1900 
1901 
1902 

280,196 
422,239 
430.450 
439,590 

$    858,856 
1,358,968 
1,561,898 
1,785,188 

The  amount  and  value  of  coke  exported  from  the  United  States 
have  increased  each  year  since  1895,  as  seen  in  the  above  table. 

The  prices  obtained  for  this  coke  per  ton,  are  as  follows:  1895, 
$3.2375;  1898,  $3.01;  1900,  $3.2175;  1902,  $4.06. 


140 


TREATISE  ON  COKE 


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TREATISE  ON  COKE 


141 


CONDITION  OF  COAL  CHARGED  INTO  COKE  OVENS,  WHETHER  RUN- 

OF-MINE,  SLACK  OR  SCREENED,  WASHED  OR  UNWASHED, 

DURING  THE  YEAR  1902 


State  or  Territory 

Run-of-Mine 

Slack  or  Screened 

Total 

Unwashed 

Washed 

Unwashed 

Washed 

Alabama 

1,233,117 
831 
28,600 

5,000 

161,783 
21,615,568 
287,064 

1,018,148 

1,262,393 
6735,194 

509,376 

3,947 
1,766 
28,159 

99,628 

602,287 
334,109 

68,546 

290 
641,422 

14,126 
91,496 

10,430 
208 

19,618 
1,623,624 
47,161 

697,962 

2,517,223 
117,528 

2,494,708 
1,052,935 
101,042 

106,987 
19,935 
140,466 

40,735 

38,000 
1,175,847 
357,530 

298,963 
255 

4,237,491 
1,695,188 
129,642 

110,934 
35,827 
265,121 

10,430 
99,628 
40,943 

219,401 
25,017,326 
1,025,864 

1,716,110 
68,546 
4,078,579 

852,977 

Colorado"  
Georgia  
Illinois6 

Indiana6  

Indian  Territory. 
Kansas  .  .  . 

Kentucky  

Massachusetts6  .  . 
Missouri  
Montana  

New  Mexico  .  .  . 
New  York  
Ohio  

Pennsylvania.  .  .  . 
Tennessee  

Utah. 

Virginia  
Washington 

West  Virginia  .  .  . 
Wisconsin  1 
Wyoming  / 

Totals  .    . 

26,347,698 

1,647,818 

5,781,088 

5,827,403 

39,604,007 

."Includes  Utah. 
6  Includes  Illinois,  Indiana,  and  Massachusetts. 

The  above  table  shows  that,   as  a  general  average  with  all 
kinds  of  coal,  it  required  1.5591  tons  of  coal  to  make  1  ton  of  coke. 


CONDITION   OF   COAL   USED   IN   THE   MANUFACTURE   OF   COKE 
THE  UNITED  STATES,  FROM  THE  YEAR  1890  TO  1902, 
INCLUSIVE  (NET  TONS) 


IN 


Year 

Run-of-Mine 

Slack  or  Screened 

Total 

Unwashed 

Washed 

Unwashed 

Washed 

1890 

14,060,907 

338,563 

2,674,492 

931,247 

18,005,209 

1891 

12,255,415 

290,807 

2,945,359 

852,959 

16,344,540 

1892 

14,453,638 

324,050 

3,256,493 

779,156 

18,813,337 

1893 

10,306,082 

350,112 

3,049,075 

1,211,877 

14,917,146 

1894 

9,648,750 

405,266 

3,102,652 

1,192,082 

14,348,750 

1895 

15,609,875 

237,468 

3,052,246 

1,948,734 

20,848,323 

1896 

11,307,905 

763,244 

4,685,832 

1,937,441 

18,694,422 

1897 

13,234,985 

1,037,830 

4,180,575 

2,453,929 

20,907,319 

1898 

16,758,244 

1,672,972 

4,487,949 

2,330,405 

25,249,570 

1899 

20,870,915 

1,457,961 

4,796,737 

2,913,730 

30,219,343 

1900 

21,062,090 

1,369,698 

5,677,006 

4,004,749 

32,113,543 

1901 

23,751,468 

1,600,714 

4,546,201 

4,309,582 

34,207,965 

1902 

26,347,698 

1,647,818 

5,781,088 

5,287,403 

39,604,007 

142 


TREATISE  ON  COKE 


In  the  preceding  table,  the  columns  of  washed  coal  indicate  in 
a  marked  manner  that  coke  makers  have  entered  into  an  era  of 
washed  coal  in  the  manufacture  of  coke.  This  gradual  increase 
in  coal  washing  also  indicates  the  reduction  of  the  areas  of  coking- 
coal  lands  whose  coal  required  no  washing  for  use  in  coke  ovens. 

AVERAGE  VALUE    PER  NET  TON  OF  COKE,  AT  THE    OVENS,  MADE 

IN   THE   UNITED    STATES,   FROM    1897    TO    1902, 

BY  STATES  AND  TERRITORIES 


State  or  Territory 

1897 

1898 

1899 

1900 

1901 

1902 

Alabama     

$2.140 
2.916 
1.280 
3.450 
1.500 
1.410 
1.500 
6.890 
2.250 
2.480 
1  .  5306 
1.810 

1.400 
4.420 
1.310 
1.870 
1.995 

4.300 
3.000 

$2.030 
2.590 
1.560 
2.833 
1.544 
1.448 
1.420 
6.906 
2.095 
2.470 
1  .  5006 
1.630 

1.317 
4.270 
1.260 
2.020\ 
1.750J 

d 

3.500 
3  .  500 

$2.03 
2.51 
2.30 
2.96 
2.13 
1.99 
1.93 
6.32 
2.25 
3.04 
1.696 
1.95 

1.73 
4  98 
1.53 

2.35 

d 

d      • 

3.75 

2.46 

$2.667 
2.820 
2.849 
3.990 
2.520 
2  .  465 
2  520 
6.159 
2.909 
2.690 
2.220 
2.670 

2.137 
4.797 
2.010 

2.870 

$2.820 
2.420 
2.830 
4.140 
2.110 
2.070 
2.099 
5.918 
2.840 
2.750 
1.885 
2.358 

1  .  635 

4.858 
1.800 

2.849 

$3.250 
2.740 
3.643 
4.100 
2.617 
2.505 
2.500 
6.750 
3.178 
3.370 
2.330 
2.850 

2.065 
4.940 
2.318 

3.446 

Colorado"  
Georgia 

Indian  Territory  . 
Kansas             .... 

Kentucky  

Missouri  

Montana  

New  Mexico  
Ohio 

Pennsylvania  .... 
Tennessee  
Utah0  

Virginia  

Washington 

West  Virginia  .... 
Illinois            

Indiana  

Massachusetts  .  .  . 
Michigan  

New  York  
Wisconsin  
Wyoming  

Average  

$1.663 

$1.594 

$1.76 

$2.310 

$2.039 

$2.490 

c  Included  with  Colorado. 

d  Included  with  Pennsylvania. 


a  Includes  Utah. 

6  Average  value,  including  New  York, 
and  also  Massachusetts  in  1899. 

NOTE. — The  great  majority  of  prices  secured  for  coke  at  ovens  in  the 
above  table  shows  that,  excepting  the  brief  boom  times,  very  little  if  any 
margin  of  profit  has  been  secured;  in  fact,  during  some  of  these  years  coal 
was  receiving  prices  equal  to,  if  not  above,  that  of  coke. — ED. 

TOTAL  VALUE   OF   COKE,  AT  THE   OVENS,  MADE  IN  THE  UNITED 
STATES,  FROM   1880  TO   1902 


Year 

Value 

Year 

Value 

Year 

Value 

1880 

$  6,631,265 

1888 

$12,445,963 

1896 

$21,660,729 

1881 

7,725,175 

1889 

16,630,301 

1897  . 

22,102,514 

1882 

8,462,167 

1890 

23.215.302 

1898 

25,586,699 

1883 

8,121,607 

1891 

20,393,216 

1899 

34,670,417 

1884 

7,242,878 

1892 

23,536,141 

1900 

47,443,331 

1885 

7,629,118 

1893 

16,523,714 

1901 

44,445,923 

1886 

11,153,366 

1894 

12.328,856 

1902 

63,339,167 

1887 

15,321,116 

1895 

19,234,319 

TREATISE  ON  COKE 


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State  or  Te 

144  TREATISE  ON  COKE 

In  the  preceding  tables  a  steady  increase  both  in  the  number 
of  plants  and  ovens,  as  well  as  in  total  output,  will  be  noticed. 
It  is  of  interest  also  to  notice  the  increased  capacity  of  the  individual 
ovens.  In  1880,  12,372  ovens  produced  a  total  output  of  3,338,300 
short  tons  of  coke,  an  average  of  270  short  tons  per  oven.  During 
the  year  1902,  there  were  in  active  operation  67,124  ovens,  which 
produced  25,401,730  short  tons  of  coke,  an  average  of  378.4  tons 
per  oven.  In  1901,  the  total  number  of  active  ovens  was  61,396 
which  produced  21,795,883  tons  of  coke,  an  average  of  355  tons 
per  oven,  showing  that  the  average  productive  capacity  of  each 
oven  in  1902  exceeded  that  of  the  preceding  year  by  23.4  tons. 


CHAPTER  V 


MANUFACTURE  OF  COKE 

Methods  of  Coking  Coal. — Coking  is  the  art  of  preparing  from 
bituminous  or  other  coal  a  fuel  adapted  for  metallurgical  and 
other  special  uses.  The  operation  consists  in  expelling  by  heat 
the  gaseous  elements  from  coking  coals,  leaving  the  fixed  and 
deposited  carbon,  ash,  and  the  residue  of 
sulphur  and  phosphorus.  These  consti- 
tute what  is  known  as  coke.  There  are 
three  principal  methods  now  in  general  use 
in  the  manufacture  of  coke:  (1)  Coking 
the  coal  in  heaps  or  mounds,  in  the  open 
air;  (2)  coking  the  coal  in  the  beehive  or 
round  oven  partly  enclosed,  with  the  air 
partially  excluded;  (3)  coking  in  retort  or 
closed  ovens,  with  air  almost  entirely 
excluded.  In  these  methods  there  are 
some  modifications,  but  the  governing 
principles  are  maintained  in  whole  or  part. 
The  open-pit  method  is  rapidly  disap- 
pearing, as  it  is  wasteful  of  the  coal  and 
tedious  in  operation.  The  beehive  coke 
oven  holds  its  place  firmly  from  its 
moderate  cost  in  construction  and  sim- 
plicity in  operation,  with  its  product  of 
the  best  possible  metallurgical  fuel.  The 
retort  coke  oven,  with  its  supplemental 
apparatus  for  saving  of  by-products, 
affords  many  advantages  in  special  localities  and  under  favorable 
conditions,  but  from  its  large  cost  in  construction  and  installation, 
with  the  expert  agencies  required  in  its  operations,  it  cannot  hope 
for  general  application. 

Coking  Coal  in  Heaps  or  Mounds. — The  open-air  coking  in 
heaps  or  mounds  has  been  copied  from  the  mounds  of  the  charcoal 
burners.  This  primitive  and  wasteful  mode  of  coking  requires  a 
yard  made  by  leveling  the  ground  and  surfacing  it  with  coal  dust. 
The  coal  to  be  coked  is  then  arranged  in  rectangular  heaps  or 

145 


(b) 
BENNINGTON  COKE  PITS 


146  TREATISE  ON  COKE 

mounds,  Fig.  1,  with  longitudinal  transverse,  and  vertical  flues; 
sufficient  wood  having  been  distributed  in  these  to  ignite  the  mass 
of  coal. 

Beginning  on  the  prepared  floor,  a  base  of  coal  a  14  feet  broad 
is  spread  to  a  height  of  18  inches.  On  this  base  the  flues  are 
arranged  and  constructed  as  shown  in  the  plan  (a),  the  flues  being 
built  of  refuse  coke  and  lump  coal  and  covered  with  suitable 
billets  of  wood.  The  coal  is  piled  up  as  shown  in  the  cross- 
section  (6).  When  the  mound  is  ready  for  coking,  fire  is  applied 
at  the  base  of  the  vertical  flues  c,  c,  igniting  the  kindling  wood  at 
each  alternate  flue.  As  the  process  advances,  the  fire  is  extended 
in  every  direction,  until  the  whole  mass  is  ignited. 

Considerable  attention  is  required  in  this  method  of  coking  in 
constructing  the  mounds,  in  diffusing  the  fire  evenly  through  the 
mass,  in  preventing  waste  by  admitting  the  proper  volume  of  air, 
and  in  banking  up  the  mounds  with  fine  dust  as  the  coking  opera- 
tion is  completed  from  base  to  top. 

When  the  gaseous  matters  have  been  expelled,  which  is  seen 
when  flames  cease  to  appear,  the  whole  heap  is  closed  up  with  fine 
dust  and  partially  smothered  out.  The  final  operation  consists 
in  the  application  of  small  quantities  of  water  delivered  by  a  hose 
down  the  flues,  which  is  quickly  converted  into  steam  permeating 
the  whole  mass  of  coke.  This  gives  coke  with  freedom  to  develop 
cells  and,  under  careful  management,  with  a  small  percentage  of 
moisture.  The  time  required  for  coking  a  mound  of  the  dimen- 
sions given,  without  limiting  its  length,  is  from  5  to  8  days,  depend- 
ing on  the  state  of  the  weather. 

The  yield  of  coke,  at  the  Bennington  yard,  is  as  follows: 

GROSS  TONS 

Coal  used  in  mound 56 . 87 

Coke  drawn  from  mound .    33 . 63 


Loss  in  coking 23 . 24 

This  primitive  method  of  coking  is  very  wasteful  of  the  coal 
and  slow  in  operation. 

Some  efforts  at  progress,  in  methods  of  coking  to  secure 
greater  economy  in  the  coal,  have  been  made  in  the  early  period 
of  evolution,  by  a  plan  for  coking  in  open-top,  rectangular  masonry 
enclosures.  These  were  made  with  side  walls,  5  to  8  feet  in  height, 
having  air  ports  along  their  longer  sides. 

The  method  of  coking  in  these  rectangular  kilns  was  very 
similar  to  those  used  in  the  mound  coking,  but  has  little  to  com- 
mend it  in  the  economy  of  its  work.  All  that  can  be  urged  in 
its  favor  is  that  it  was  a  step  in  the  progress  of  improvement 
toward  the  modern  coke  ovens. 

The  beehive  coke  oven  followed.  The  following  analyses  will 
exhibit  the  result  of  its  work  with  the  Connellsville  coal: 


TREATISE  ON  COKE 


147 


ANALYSES  OF  CONNELLSVILLE  COAL  AND  COKE 


Coal 
Per  Cent. 

Coke 
Per  Cent. 

Moisture 

1  25 

88 

Volatile  matter 

31  80 

67 

Fixed,  carbon                                                 

59.79 

87.05 

Ash                                                      

7.16 

10.60 

Sulphur                                   

.53 

.74 

To  Determine  Loss  of  Carbon  in  Process  of  Coking. — To  deter- 
mine the  waste  in  coking  by  this  system,  the  fixed  carbon,  ash, 
and  sulphur  go  to  make  the  coke.  Allowing  for  the  volatilization 
of  sulphur  in  coking,  then  59.75  +  7.16  +  .44  =  67.39.  Then 
100  *.  67.39  =  1.484  tons  of  coal  to  make  1  ton  of  coke. 

The  fixed  carbon  in  the  coke  should  therefore  be,  1.484  X  59.79 
=  88.728  per  cent.;  but  it  is  only  87.05  per  cent.,  exhibiting  a 
loss  of  fixed  carbon  in  coking  of  1.882  per  cent. 

Two  additional  elements  enter  into  this  result;  the  percentage 
of  fixed  carbon  deposited  from  the  volatile  hydrocarbon  of  the 
coal,  giving  the  coke  the  silvery  glaze  that  distinguishes  it  so 
prominently.  The  other  element  is  the  moisture  in  the  coke; 
the  percentage  of  this  depends  on  the  care  exercised  in  quenching 
or  cooling  the  incandescent  coke  in  the  beehive  oven,  ranging 
from  1  to  3  per  cent. 

The  actual  loss  of  fixed  carbon  in  coking  would  be  the  calcu- 
lated loss  plus  the  deposited  carbon  minus  the  moisture  remain- 
ing in  the  coke.  Some  of  the  volatile  matter  in  the  slates  and 
shales  forming  the  ash  will  be  volatilized  in  the  process  of  coking, 
but  this  is  so  small  an  element  that  practically  it  is  disregarded. 
The  conditions  of  carbon  deposit,  with  the  percentage  of  moisture 
in  the  coke,  will  hold  in  all  the  methods  of  coking.  It  is  also  evident 
that  the  higher  the  percentages  of  fixed  carbon  and  ash  in  any 
coal,  the  greater  the  aggregate  percentage  of  the  product  in  coke. 

A  recent  test  of  a  sample  of  the  Kanawha  Valley  coke,  made 
from  the  rich  bituminous  coal  of  that  region,  will -further  illustrate 
the  method  of  determining  the  loss  of  fixed  carbon  and  other 
elements  in  the  coal  in  the  coking  process. 

ANALYSES  OF  KANAWHA  VALLEY  COAL  AND  COKE 


Coal 
Per  Cent. 

Coke 
Per  Cent. 

Volatile  matter                                                        .  .  . 

34  .  7900 

.000 

Fixed  carbon                                                   

57.8600 

89.200 

Ash                                                     

6.2000 

9.500 

Sulphur  

1.1500 

1.300 

Phosphorus                                                                 •  • 

.0157 

.024 

148 


TREATISE  ON  COKE 


From  the  foregoing  analyses  it  is  evident  that,  taking  the 
fixed  carbon,  ash,  and  74  per  cent,  of  sulphur,  we  have  57.96  +  6.20 
+  .85  =  64.91.  Hence,  100  H-  64.91  =  1.540  tons  of  coal  to  make 
1  ton  of  coke. 

The  fixed  carbon  in  the  coke  is  therefore  57.86  X  1.540  = 
89.10  per  cent.;  but  by  analysis  it  is  89.20  per  cent.,  exhibiting  a 
slight  gain  of  this  element.  This  is  secured  from  the  large  deposit 
of  carbon  glaze  from  this  very  rich  bituminous  coal.  The  other 
elements  in  the  coke  can  be  determined  on  the  above  general 
principles. 


BEEHIVE  COKE  OVEN 

The  name  beehive  evidently  had  its  genesis  in  the  close  resem- 
blance of  the  internal  form  of  this  oven  to  the  ancient  dome-shaped 
beehive. 

The  initial  form  of  the  beehive  coke  oven  is  given  in  Fig.  2, 
which  shows  the  effort  to  introduce  a  partially  enclosed  oven  early 

in  the  manufacture  of  coke. 
It  is  not  very  clear  whether 
this  plan  of  oven  was  sug- 
gested by  the  form  of  the 
dome-shaped  mound  method 
of  coking  coal  or  from  the 
charcoal  kilns.  It  was  built 
with  refractory  materials  and 
in  some  instances  had  flues 
in  its  heavy  walls. 

The  product  of  this  oven 
could  not  differ  much  from 
that  of  the  modern  beehive 
oven  of  1880, 1890,  and  1902, 
only  the  waste  of  carbon  in 
the  former  was  much  more 
than  in  the  improved  oven. 
The  ancient  beehive  oven 
was  originally  constructed 
on  a  diminutive  scale  in  the 
"day  of  small  things,"  but 
it  has  continued  to  grow  in 
size  through  a  century  and 
a  half  until  it  has  attained 
dimensions  of  12  feet  to  13  feet  in  diameter,  with  a  height  of  dome 
above  the  floor  of  7  feet  to  8  feet.  The  height  of  the  door  of  this 
oven  has  been  increased  so  as  to  admit  the  air  at  a  level  somewhat 
above  the  charge  of  coking  coal  to  prevent  the  waste  formerly 

*From  Mr.  A.  L.  Steavenson,  in  Vol.  VIII.,  North  of  England  Mining 
Engineers,  1860 


FIG.  2. 


Section  plan 

PLAN  OP  COKE  OVENS  NEAR  NEWCASTLE- 

UPON-TYNE* 


-\ 


L 


17303— v 


FIG.  3.     WORKING  PLAN  FOR  THE  CONSI 


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a 


tL    r-***-V 
«f   /  .     \.«*» 

T       U—  2^' 
d 


•ION  OF  BEEHIVE  OVENS,  OLIVER  PLANT 


S^ 


^i.n.1 


TREATISE  ON  COKE 


149 


150  TREATISE  ON  COKE 

sustained  at  this  place  by  contact  of  the  air  with  the  coke  in  low- 
door  ovens,  leaving  a  deposit  of  ashes  along  the  line  of  this  air  draft. 

A  number  of  improvements  have  been  made  in  the  construction 
of  this  oven,  especially  in  the  preparation  of  shaped  firebrick  for 
doors,  jambs,  dome,  and  charging  port.  In  addition  to  these 
improvements,  recent  practice  has  secured  the  use  of  silica  brick 
for  the  dome,  increasing  greatly  the  wearing  properties  of  the 
oven,  especially  in  this  portion  of  it,  which  is  subjected  to  the 
most  intense  heat  in  the  coking  operations.  Mr.  O.  W.  Kennedy 
introduced  the  use  of  silica  brick  and  estimates  that  they  will 
wear  three  to  four  times  as  long  as  the  fireclay  brick. 

In  some  ovens,  an  annular  passage  for  the  admission  of  air, 
with  perforations  for  its  equal  distribution  above  the  level  of  the 
charge  of  coal,  has  been  tried  with  increased  economy  in  saving 
the  burning  of  the  carbon  of  the  coal. 


BEEHIVE  OVEN  OF  1894 

Beehive  Oven,  1894  Type. — Fig.  3  exhibits  working  plan  with 
details  of  the  usual  method  of  constructing  this  oven,  dating  about 
the  year  1894.  A  bank  of  a  double  row  of  this  class  of  ovens  was 
constructed  near  Gallitzin  on  the  Alleghany  Mountain.  The  design 
was  to  coke  coals  from  the  Upper  Kittanning  (B)  and  the  Upper 
Freeport  (E)  seams.  As  these  coals  are  only  medium  in  fusing 
matter,  the  moderate  size  of  this  oven  answered  the  purpose  very 
successfully. 

Beehive  Oven  at  Oliver  Plant. — A  plan  and  section  given  in 
Fig.  4  illustrate  the  larger  beehive  coke  ovens  more  recently  con- 
structed at  the  Oliver  plant,  near  Uniontown,  in  the  Connellsville 
region.  These  have  been  kindly  furnished  by  Messrs.  Wilkins  and 
Davison,  engineers,  Pittsburg,  Pennsylvania,  who  are  experts  in 
this  and  kindred  constructions. 

The  interlocking  plan  shown  in  the  bank  of  coke  ovens,  Fig.  4, 
is  sometimes  used  to  compact  more  closely  the  group  of  ovens;  at 
other  localities,  it  is  adopted  to  economize  space  where  the  ground 
for  the  ovens  is  limited. 

Continental  Coke  Oven. — Fig.  5  exhibits  plans  and  sections 
with  detailed  drawings  of  the  coke  ovens  of  the  Continental  Coke 
Company's  works,  No.  1,  near  Uniontown,  Fayette  County,  Penn- 
sylvania. These  ovens  are  in  the  Connellsville  coke  region  and  are 
of  the  modern  enlarged  plan  of  the  beehive  coke  oven. 

The  section  in  Fig.  6  shows  an  arrangement  for  an  extended 
works  where  ample  ground  can  be  secured.  These  two  figures 
show  plans  and  sections  of  the  coke  ovens,  wharves,  and  railroad 
sidings,  with  dimensions  given  in  full  details.  These  several 
banks  of  ovens  with  their  respective  coke  wharves  have  been  built 


NMl 


— ^ 

\A 


r 


FIG.  5.     BEEHIVE  Ov 


17303— v 


FIG.  6.     ARRANGEMENT  OF  OVENS  A 


CONTINENTAL  COKE  Co. 


rCRKS  OF  THE  CONTINENTAL  COKE  Co. 


Tile. 


Yard  Level 


151 


Dry  Masonry , 
FIG.  7  (a) 


152 


TREATISE  ON  COKE 


FRONT ELEVA  TION 
FIG.  7  (fe) 


up  from  the  low  ground 
and  involve  considerable 
masonry  work  as  well  as 
much  embanking.  While 
this  method  of  construc- 
tion is  expensive  in  first 
cost,  since  the  ovens  are 
raised  high  above  the 
ground,  they  are  free  from 
dampness  and  assure  the 
best  results  in  their  coke 
product. 

Wharton   Coke   Oven. 

Fig.  7  exhibits  a  modern 
plan  of  the  beehive  coke 
oven  as  it  has  been  con- 
structed in  a  plant  of  300 
ovens  at  the  Joseph 
Wharton  Coke  Works  at 
Coral,  Indiana  County, 
Pennsylvania. 

The  general  design  is 
given  in  the  drawing  with 
some  details.  The  oven 
is  12  feet  by  7£  feet.  It 
was  planned  mainly  for 
coking  coal  from  the 
upper  Freeport  bed  (E). 
This  coal,  as  well  as  all 
others  in  Indiana  County, 
requires  a  preparation  for 
use  in  manufacturing  mer- 
chantable coke  for  metal- 
lurgical uses.  The  fusing 
matter  is  not  as  high  in 
this  coal  as  in  the 
Connellsville.  At  these 
works,  to  avoid  the  pro- 
duction of  black  ends,  so 
undesirable  in  blast-fur- 
nace work,  a  subfloor  of 
red  brick  has  been  laid 
under  the  usual  tile  floor 
of  these  ovens;  this  addi- 
tional floor  stores  heat 
and  prevents  the  produc- 
tion of  black  ends,  the 


TREATISE  ON  COKE 


153 


coke  coming  out  of  the  oven  with  a  silvery  clearness  to  the  floor 
of  oven.  Another  peculiarity  of  the  construction  of  these  ovens 
is  the  second  sustaining  arch  over  and  supplementary  to  the  heavy 
jamb  brick  arch  over  the  door  of  the  oven.  This  higher  arch  is 
designed  to  sustain  the  front  of  the  oven  structure  while  repairs 
are  being  made  to  the  large  shaped  brick  in  the  arch  and  jambs 
of  the  ovens,  without  the  labor  and  expense  of  tearing  down  a 
large  section  of  the  oven.  Silica  brick  were  used  exclusively  in 
the  domes  or  crowns  of  these  ovens.  This  will  conduce  greatly  to 
the  length  of  their  work  and  economy  in  their  repairs. 

The  section  shown  in  Fig.  8  illustrates  the  arrangements  of  the 
ovens  with  the  ample  wharf  room,  the  retaining  wall,  and  railroad 


FIG.  8 


siding,  with  related  elevations  to  secure  the  utmost  facilities  in  the 
manufacture  and  shipment  of  the  coke. 

It  may  be  noted  here  that  the  operations  of  the  modern  beehive 
coke  oven  secure  two  desirable  properties  in  metallurgical  coke,  viz.  : 
its  full  cellular  developments,  assuring  the  maximum  calorific 
energy  in  its  combustion,  and  its  dry  condition  with  minimum 
percentage  of  moisture. 

It  may  be  conceded,  however,  that  the  cost  of  labor  and  waste 
of  carbon  in  coking  in  the  beehive  oven  are  somewhat  in  excess  of 
similar  work  in  some  of  the  modern  retort  coke  ovens. 

This  plant  of  beehive  coke  ovens  at  the  Wharton  works  is 
very  complete  in  all  its  parts  and  is  a  model  in  its  design  and 
construction. 

The  general  plan  of  this  large  plant  of  coke  ovens  was  matured 
by  Mr.  Harry  McCreary,  general  superintendent,  ably  assisted  by 
Mr.  R.  M.  Mullen,  civil  engineer.  The  estimated  cost  of  one  oven 
of  the  Wharton  type,  in  1903,  is  given  in  table  on  page  154. 


CONSTRUCTION  OF  THE  MODERN  BEEHIVE  OVEN 

Excavation  for  Foundations. — The  excavation  for  all  founda- 
tions for  masonry  work  should  be  cut  to  such  depth  beneath  the 
surface  of  the  ground  as  will  assure  stability  to  the  masonry  and 
exemption  from  its  disturbance  by  frost.  The  depth  and  general 


154 


TREATISE  ON  COKE 


foundation  conditions  must  be  studied  in  each  locality,  and  should 
be  under  the  direction  of  a  competent  engineer,  or  such  agent  as 
the  management  may  appoint. 

Masonry  of  Retaining  Walls. — The  masonry  of  the  retaining 
walls  of  the  coke  ovens  should  be  laid  dry  with  sound  sandstones,  of 
even  beds  and  of  such  thickness  as  hereafter  described.  This  dry- 
laid  foundation  should  be  carried  to  the  level  of  the  coke  wharf  in 
front  of  the  coke  ovens.  Above  this  foundation  course  the  masonry 
should  be  laid  in  lime  mortar  or  cement,  composed  of  two  parts  of 
clean,  sharp  sand  and  one  part  of  good  slacked  lime  or  cement, 

ESTIMATED  COST  OF  ONE  WHARTON  COKE  OVEN 


Price 

Amount 

1  254  lining  brick         

$18.00 

$22  .  57 

2  487  crown  brick   silica  brick 

18.00 

44.76 

113  tile  12  in  X  12  in  X  3  in                                             

55.00 

6.22 

1  set  arches  and  iambs                                            .         

8.00 

8.00 

770  paving  brick  in  bottom  of  oven       

8.00 

6.16 

660  mill  brick  in  front  of  oven             

8.00 

5.28 

2.00 

2.00 

1  cast-iron  door  frame 

5  00 

5  00 

30  lineal  feet,  70-pound  cross-rail  to  carry  larry  rail  —  1 
700  pounds                                                    .      ....".    .  .      J 

30.00 

10.50 

29  lineal  feet,  70-pound  larry  rail,  655  pounds  
14  lineal  feet,  cast-iron  water  pipe,  434  pounds  
13  4  cubic  yards  mortar  wall        .  .  .  .'  

30.00 
.02 
2.75 

9.80 
8.68 
36.85 

1  .  5  cubic  yards  brickwork  in  front  of  oven  
Building  oven  complete  

4.90 
29.25 

7.35 
29.25 

125  cubic  yards  excavation  for  oven  seat,  yard,  and! 
railroad                                                                           •           / 

.40 

50.00 

7  railroad  ties                                                        

.35 

2.45 

28   lineal   feet,   70-pound   rail   for  railroad   track  —  6551 
pounds                               J 

30.00 

9.83 

20  cubic  vards  of  dry  wall  per  oven  

2.35 

47.00 

Total  cost  of  oven 

$311  70 

the  whole  carefully  mixed  to  secure  a  thorough  blending  of  these 
materials.  The  building  stones  should  be  sufficiently  large  and 
broad-bedded  for  this  purpose  to  assure  good  bond  and  strong 
work  to  resist  the  alternating  pressures  from  the  heat  changes  in 
the  coking  operations.  Flagstones  with  good  beds,  having  an 
average  thickness  of  6  inches  to  8  inches,  should  be  used  in  the 
retaining  wall  above  the  level  of  the  floor  of  the  oven. 

The  outer  face  of  the  masonry  should  be  neatly  trimmed  and 
the  bedding  of  the  stones  dressed  to  lie  firmly  on  each  other  without 
the  aid  of  chips  or  pinners.  The  face  of  this  wall  should  be  carried, 
up  with  a  uniform  batter  of  at  least  2  inches  to  the'  vertical  foot. 
Great  care  should  be  taken  in  embedding  the  stones  in  the  mor- 
tar and  thoroughly  filling  all  joints  and  interstices.  Seats  for  the 


TREATISE  ON  COKE  155 

bases  of  the  iron  door  frames  of  the  oven  should  be  carefully 
dressed  to  an  even  surface  to  assure  stability  at  this  important 
part  of  the  ovens.  The  arch  piece  of  this  iron  door  frame  is  to 
be  omitted,  as  its  expansion  under  heat  has  been  found  to  be  a 
disturbing  element  to  the  jambs  and  supplementary  arches. 

Building  the  Coke  Oven. — The  foundation  under  the  oven 
should  be  cleared  of  all  vegetable  or  combustible  matter  and  the 
foundation  of  the  circular  wall  should -begin  on  firm  materials — 
whether  on  rammed  embanking  ground  or  in  excavations  under  the 
surface.  The  building  of  the  oven  should  conform  accurately  to  the 
plan  selected  for  the  locality.  It  should  be  built  of  shaped  firebrick 
and  silica  brick  composed  of  materials  especially  adapted  for  the 
service  demanded  in  their  use  in  the  oven — strong  heats  with  water 
contact  in  the  quenching  or  cooling  of  the  coke  charge  in  the  oven. 

The  circular  section  of  the  oven,  from  the  foundation  to  the 
springing  of  the  arch  of  the  dome  or  crown,  should  be  built  with 
firebrick  shaped  to  conform  to  the  radial  lines  of  this  portion  of 
the  oven.  The  physical  composition  of  these  firebrick  should  con- 
sist of  coarsely  ground  fireclay  to  provide  •  for  the  expansion  by 
heat  and  the  shrinkage  by  water  under  these  conditions  in  the 
coking  operations.  The  dome  or  crown  of  the  oven  should  be 
built  with  silica  brick,  holding  not  over  2  per  cent,  of  lime  in  com- 
bination. They  should  be  shaped  to  conform  to  the  radial  planes 
of  this  portion 'of  the  oven  to  secure  compactness  and  stability, 
and  the  whole  should  be  keyed  firmly  by  the  charging  port  ring 
in  the  crown  of  the  oven. 

The  lines  of  the  oven  should  be  defined  by  sweeps  from  a 
central  pivoted  stake.  The  oven  door  jambs,  with  shaped  arch 
brick  connections,  should  be  neatly  and  carefully  laid.  The  supple- 
mentary brick  arch  to  maintain  the  front  wall  of  the  oven  above 
its  door  should  be  constructed  on  firmly  set  skew  backs  at  the 
springings  of  this  arch.  The  mortar  to  be  used  in  setting  the  fire- 
brick work  of  the  oven  should  be  composed  of  loam,  or  loamed 
clay,  in  such  proportions  as  may  be  deemed  most  serviceable.  A 
mortar  of  ground  fireclay  and  loam  may  be  used  in  this  work. 

The  tiles  on  the  bottom  of  the  oven  should  have  a  rise  from  the 
door  to  the  back  of  the  oven  of  6  inches.  They  should  rest  on  a 
thin  stratum  of  sand  on  top  of  the  subfloor  of  the  oven.  This 
subfloor  is  to  be  built  of  red  brick,  laid  on  edge,  in  a  sand  bed  on  a 
firmly  compacted  foundation.  The  use  of  this  red-brick  subfloor  is 
to  store  heat  to  prevent  the  production  of  "black  ends "  in  the  coke. 

The  filling  under  and  around  the  oven  should  be  made  with 
selected  earth,  and  all  vegetable  or  unsuitable  matters  removed. 
The  filling  should  be  made  in  horizontal  layers,  not  exceeding 
1  foot  in  thickness  It  should  be  thoroughly  wet  and  packed 
solidly  with  rammers  or  rollers  to  prevent  shrinking  and  settling. 
To  assure  stability  in  this  filling  sufficient  time  should  be  allowed 
it  to  settle  and  to  partially  dry. 


156 


TREATISE  ON  COKE 


TREATISE  ON  COKE  157 

The  larry  track  should  be  made  with  T  rails,  weighing  70  to 
80  pounds  per  lineal  yard,  to  be  laid  on  iron  cross-ties  or  iron 
girders  with  necessary  chair  fastenings.  When  a  double  row  of 
coke  ovens  is  constructed,  the  larry  track  should  be  placed  midway 
between  the  charging  ports  of  the  ovens.  In  this  case,  the  larry 
should  have  discharging  chutes  on  each  side. 

Cast-Iron  Water  Pipe. — A  cast-iron  water  pipe  4  inches  in 
diameter,  weighing  at  least  18^  pounds  per  lineal  foot,  should  be 
laid  with  its  top  surface  18  inches  below  wharf  level,  with  taps 
for  coke-oven  valve  for  each  two  coke  ovens,  with  Powell's  star 
coke-oven  valve  on  top. 

Coke  Wharf. — The  level  of  the  coke  wharf  should  be  2  feet 
6  inches  below  the  sill  of  the  iron  door  of  the  oven,  with  a  moderate 
inclination  to  the  edge  of  the  wharf  wall.  The  width  of  the  coke 
wharf  should  be  at  least  40  feet.  The  level  of  heads  of  rails,  on 
the  railroad  siding,  should  be  made  of  such  grade  under  the  level 
of  the  wharf  as  to  secure  ample  height  for  loading  the  coke  into  the 
railroad  cars,  from  7  feet  to  12  feet.  The  grade  of  the  cove  ovens 
should  be  1  foot  to  100  feet  (1  per  cent.)  where  it  is  practicable, 
and  the  railroad  sidings  of  similar  gradients.  This  will  secure 
descending  gradients  with  the  tonnage  and  secure  easy  handling 
of  railroad  cars  without  the  necessity  of  a  locomotive. 

Measurements. — All  the  stone  masonry  necessary  to  the  com- 
pletion of  the  coke  ovens  is  measured  in  the  wall  with  the  dimen- 
sions as  given  on  the  plan.  All  masonry  is  measured  and  paid 
for  by  the  cubic  yard  of  27  cubic  feet.  These  measurements  are 
the  actual  cubical  contents  without  any  allowances. 

The  brickwork  in  the  coke  ovens  is  paid  for  by  the  oven. 
This  includes  the  laying  of  the  jamb  brick,  facing  brick,  tiles, 
silica  brick,  and  all  other  work  of  this  description  in  the  complete 
construction  of  the  coke  ovens.  All  excavation  and  filling  are 
paid  for  by  the  cubic  yard. 

The  engineer  or  agent  should  issue  directions  from  time  to  time 
as  the  work  progresses,  and  these  should  be  carried  out  strictly 
in  accordance  with  his  instructions.  In  all  cases,  the  decision  of 
the  engineer  or  agent,  in  the  method  of  the  construction  of  the 
work  and  in  the  estimate  of  quantities,  should  be  final  and  con- 
clusive between  the  contracting  parties. 

Fig.  9  will  be  interesting  as  showing  the  process  of  the  con- 
struction of  these  beehive  coke  ovens. 


THE  COKING  PROCESS 

For  the  purpose  of  determining  its  exact  percentage  of  coke 
product,  an  exhaustive  series  of  experiments  was  made  at  the 
large  coking  plants  of  the  Cambria  Iron  Company,  in  12'  X  6' 
beehive  ovens,  in  the  Connellsville  region  under  the  care  of  Mr. 
Isaac  Taylor. 


158  TREATISE  ON  COKE 

The  cross-sections  of  48-  and  72-hour  charges  of  coal  in  these 
ovens,  Figs.  10  and  11,  will  show  the  process  of  coking  from  top 
of  charge  to  floor  of  oven,  with  the  enlargement  and  shrinkage  of 
the  resultant  coke  carefully  and  accurately  defined  from  the 
actual  work  of  these  ovens. 

From  the  sections,  Figs.  10  and  11,  and  the  Tables  I  and  II,  it 
will  be  readily  seen  that  the  average  charge  of  coal  for  48-hour 
coke  is  9,910  pounds,  or  5  net  tons  nearly.  It  occupies  a  depth 
in  the  coke  oven  of  23  inches.  The  charge  of  coal  for  72-hour  coke 
is  11,915  pounds,  or  6  net  tons  nearly.  It  has  a  depth  in  the  oven 
of  26|  inches.  These  sections  show,  in  a  graphic  way,  the  heights 
of  48-  and  72-hour  coke  in  the  ovens  at  "best,"  and  its  reduced 
altitude  after  being  cooled  by  watering  in  the  oven.  The  process 
of  fusing  and  coking  begins  on  the  top  surface  of  the  charge  of  coal, 
and  goes  down  through  the  mass  of  coal  at  the  rates  shown  in 
the  margins  of  the  sections,  until  it  reaches  the  bottoms  of  the  ovens. 

It  will  also  be  seen  that  in  this  process  of  coking  hydrocarbon 
gas  will  be  evolved  from  the  coal,  which  gas,  passing  up  through 
the  fissures  of  the  incandescent  section  of  coked  coal,  deposits 
some  of  its  carbon.  This  gives  the  coke  the  bright  silvery  coating 
that  distinguishes  the  best  cokes  and  partly  protects  them  from 
dissolution  in  the  upper  region  of  blast  furnaces  from  the  action 
of  the  ascending  gases. 

The  tables  of  careful  tests,  I  and  II,  show  in  accurate  detail 
two  series  of  determinations  to  learn  the  exact  percentage  of  coke 
produced,  under  careful  management  in  the  beehive  coke  oven. 
They  give  the  average  results  from  an  equal  number  of  tests  of 
48-  and  72-hour  charges  of  coal  in  the  product  of  coke. 

Table  I  shows  the  usual  and  practical  percentage  of  coke  made 
in  these  ovens  in  the  usual  way  with  the  moisture  from  cooling  in 
the  oven  included.  Table  II  shows  the  exact  percentage  of  coke 
as  it  has  been  drawn  in  a  red-hot  condition  and  exempt,  or  nearly 
so,  from  moisture.  This  latter  determination  is  impracticable,  but 
it  was  made  to  ascertain  the  ratio  of  carbon  waste  by  the  beehive- 
oven  method  of  coking. 

In  all  these  experimental  tests,  the  coal  charged  into  ovens  and 
the  products  in  marketable  coke,  fine  coke,  or  breeze,  and  ashes, 
have  been  carefully  separated  and  accurately  weighed. 

In  the  preparation  of  these  tables,  samplings  of  the  coal  used 
and  coke  made  were  analyzed  by  the  late  Dr.  James  J.  Fronheiser, 
in  the  Cambria  Iron  Company's  laboratory  at  Johnstown,  Pennsyl- 
vania, with  the  following  results: 

CONNELLSVILLE     CONNELLSVILLE 
COAL  COKE 

Moisture  at  212°  F 1 . 25  .63 

Volatile  matter 31 . 27  1 .  37 

Fixed  carbon 59.  79  85. 99 

Ash 7.16  11.12 

Sulphur 53  .89 


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TREATISE  ON  COKE 


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From  the  analysis  of 
Connellsville  coal  given 
on  page  158,  used  in  these 
coking  tests,  as  shown  in 
Tables  I  and  II,  it  will 
be  seen  that  the  loss  in 
the  coking  operation,  in 
the  wet  and  dry  ways,  is 
30.71  and  36.24  per  cent., 
respectively.  This  loss 
arises  from  the  expulsion 
of  moisture,  volatile  mat- 
ter, and  some  of  the  fixed 
carbon.  The  loss  of  the 
fixed  carbon  is  the  most 
important  element  in  the 
consideration  of  the  work 
of  the  beehive  and  all 
other  coke  ovens.  The 
fixed  carbon,  ash,  and 
sulphur  constitute  the 
coke.  The  sum  of  these 
in  this  instance  amounts 
to  67.48.  Dividing  100 
by  this  number  gives 
1.481,  the  number  of  tons 
of  coal  to  make  1  ton  of 
coke.  Then  the  fixed  car- 
bon in  the  coal,  59.79, 
multiplied  by  1.481,  gives 
88.549,  the  theoretic  vol- 
ume of  carbon  in  the  coke. 
Hence,  88.549  :  100  = 
85.99  :  97.11,  or  2.89  per 
cent,  of  loss  of  fixed  car- 
bon. Practically,  it  is 
more  than  this,  depend- 
ing on  the  care  in  coking 
and  cooling  the  coke  in 
the  oven. 

In  Table  II,  the  coke 
was  drawn  from  the  oven 
hot  and  weighed  in  this 
condition,  showing  that 
the  loss  of  carbon  was 
substantially  the  same  as 
in  the  former  case,  but 
the  loss  in  moisture  and 


TREATISE  ON  COKE  163 

volatile  matter  was  36.24,  exhibiting  a  reduction  in  moisture  of 
5.26  per  cent. 

A  similar  test  on  a  bank  of  beehive  ovens  at  Gallitzin,  on  the 
Alleghany  Mountains,  running  on  coal  from  the  Upper  Freeport 
seam,  required  1.383  tons  of  coal  to  make  1  ton  of  coke.  The 
loss  in  fixed  carbon  was  4.42  per  cent.  Another  test,  under 
similar  conditions,  at  a  coking  plant  in  Elk  County,  Pennsylvania, 
using  coal  from  the  Upper  Kittanning  seam,  required  1.459  tons  of 
coal  to  make  1  ton  of  coke.  The  loss  in  fixed  carbon  was  2.71 
per  cent. 

Practically,  Table  I  shows  that  Connellsville  coal,  coked  in  the 
modern  beehive  oven,  will  produce  under  careful  and  intelligent 
management  66.17  per  cent,  of  marketable  coke,  2.30  per  cent,  of 
small  coke  or  breeze,  and  .82  per  cent,  of  ashes.  This  enlarged 
product  of  coke,  66.17  per  cent.,  has  been  obtained  by  improved 
methods  in  coking,  by  reducing  the  waste  of  fixed  carbon  at  doors 
of  ovens,  and  by  increasing  their  height  so  as  to  admit  air  above  the 
charge  of  coal  in  the  oven,  thus  avoiding  the  old-time  wastage  at 
this  place.  There  is  also  a  deposit  of  carbon  from  the  expelled 
volatile  hydrocarbons  of  the  coal  in  coking  in  their  upward  passage 
through  the  incandescent  coke,  especially  noticeable  in  the  upper 
section  of  coke. 

Just  how  much  carbon  is  deposited  under  the  varying  conditions 
in  coking  48-  and  72-hour  coke  has  not  yet  been  accurately  deter- 
mined. After  some  experiments,  in  a  crucible,  in  coking  Connells- 
ville coal,  it  was  found  that,  under  conditions  similar  to  those  of 
the  beehive  oven,  and  admitting  a  proportional  volume  of  air,  the 
resultant  dry  coke  was  67.56  per  cent.,  which  is  slightly  in  excess 
of  the  theoretical  or  calculated  yield  of  coke  from  this  coal,  67.27 
per  cent.  A  second  experiment  consisted  in  the  exclusion  of  air, 
using  the  true  retort  method  in  coking.  This  gave  79.20  per  cent, 
of  coke.  We  have,  therefore,  the  two  results:  (1)  by  admitting 
air,  67.56  per  cent.;  (2)  by  excluding  air,  79.20  per  cent.;  exhibit- 
ing an  increase  by  the  latter  method  of  11.64  per  cent. 

As  the  first  coking  test  gives  the  full  theoretic  result  of  coke, 
it  is  evident  that  there  was  no  burning  or  waste  of  fixed  carbon, 
or  if  any  was  wasted  an  equal  amount  of  deposited  carbon 
must  have  replaced  it.  In  the  second  test,  there  was  evidently 
a  large  deposit  of  carbon  from  the  gases  of  the  coal,  at  least 
14.71  per  cent.,  assuming  that  no  fixed  carbon  has  been  burned 
in  this  retort  test. 

Practically,  no  construction  of  coke  oven  could  afford  the  pre- 
cision of  admitting  air  and  absolutely  excluding  it,  as  in  these 
laboratory  tests.  They  show,  however,  that  the  retort -oven 
methods  of  coking  afford  a  larger  yield  of  coke  than  can  be  obtained 
by  the  beehive-  or  air-oven  methods  of  coking.  The  relative 
calorific  values  of  the  coke  made  in  these  two  principal  methods 
will  be  taken  up  in  a  subsequent  chapter. 


164  TREATISE  ON  COKE 

Old  Welsh  Oven. — In  the  progress  of  the  manufacture  of  coke, 
the  elements  of  cost  appear  to  have  invited  attention  to  the  labo- 
rious and  expensive  methods  of  drawing  coke  from  the  old  and 
cramped  beehive  ovens.  The  main  effort  in  reducing  cost  was 
directed  to  a  new  plan  of  coke  oven,  retaining  the  principles  of  the 
beehive,  but  planning  the  new  oven  so  as  to  draw  the  coke  by 
mechanical  appliances. 

The  Welsh  oven  consists  of  an  arched  chamber  12  feet  long, 

7  feet  broad,  and  about  6  feet  high.     One  end  of  this  oven  is  walled 
up,  the  other  end  or  front  has  doors  or  luted  walls.     A  flue  chimney 
at  the  closed  end  of  the  oven  affords  egress  to  the  gases. 

The  coke  is  drawn  out  by  a  drag  composed  of  a  main  iron  bar 
running  the  length  of  the  oven  and  having  a  crosspiece  at  the 
inner  end.  The  whole  drag  is  placed  in  the  bottom  of  the  oven 
before  the  charge  of  coal  is  placed  in  it,  and  it  remains  under  the 
charge  of  coal  until  it  is  coked  and  ready  for  drawing  out,  when  a 
chain  is  attached  to  an  eye  in  the  drag  at  front  of  oven,  and  the 
coke  pulled  out  in  mass,  by  windlass  or  engine  power.  The  coke 
is  usually  quenched  or  cooled  outside  the  oven. 

With  skill,  this  method  of  coke  manufacture  possesses  some 
advantages  in  the  economy  of  the  work  in  drawing  the  coke  out 
of  oven,  without  injuriously  affecting  the  physical  condition  of  the 
coke.  The  cooling  outside  the  oven  by  watering  is  the  chief  objec- 
tionable feature  in  this  section  of  the  work  of  coking,  as  coke 
watered  in  this  way,  if  done  in  a  clumsy  manner,  will  contain  from 

8  to  15  per  cent,  of  water,  which  neutralizes  the  advantage  secured 
in  the  rapid  drawing  of  the  coke  by  mechanical  means.     This  effort 
at  the  improvement  in  the  coke  oven  to  save  labor  has  been  fol- 
lowed by  other  plans  on  the  same  general  principles,  but  mainly 
designed  at  improvement  in  the  details  of  these  methods  of  the 
several  operations  in  coking. 

The  Thomas  oven  is  simply  an  improved  Welsh  oven,  preserving 
the  desirable  properties  of  the  beehive  oven  in  coking  the  coal. 
It  secures  some  economy  over  the  latter  by  its  mechanical  method 
of  drawing  the  coke.  It  retains,  however,  the  undesirable  method 
of  cooling  the  coke  by  watering  it  outside  the  oven. 

This  oven  has  been  fully  described  in  a  paper  prepared  by 
Mr.  J.  T.  Hill,  manager  of  the  Coalburg  mine,  and  read  at  the 
meeting  of  the  Alabama  Industrial  and  Scientific  Society,  in  1891. 
Fig.  12  illustrates  its  main  features. 

The  descriptive  text  is  as  follows:  "The  essential  difference 
between  the  old  Welsh  oven  and  the  Thomas  oven  exists  in  the  fact 
that  the  latter  is  much  longer,  affording  greater  capacity,  and  that 
both  ends  are  movable,  thus  doing  away  with  the  necessity  of 
placing  the  drag  in  the  oven  prior  to  charging.  In  nearly  every 
other  respect  the  ovens  are  identical. 

"At  Coalburg  there  are  sixty-four  Thomas  ovens  arranged  in 
one  single  continuous  battery.  In  construction,  the  same  principles 


TREATISE  ON  COKE 


165 


are  carried  out  and  materials  used  as  in  the  beehive  ovens,  except 
that  the  bottoms  are  of  hard  red  brick,  upon  the  theory  that  they 
resist  wear  of  the  drag  better  than  the  firebrick.  In  detail  they 
are  described  as  follows:  length,  36  feet;  width  inside,  7  feet 
3  inches  at  back,  and  7  feet  9  inches  at  front;  height  over  all,  8 
feet;  height  of  door,  4  feet;  height  inside,  5  feet  to  crown  of  arch. 


5> 

(c) 


Cross  Sect/on  one-f?a# way 

(d) 
FIG.  12.     THOMAS  OVEN 


"Fall  in  bottom  from  back  door  to  front,  1  inch  in  3  feet,  or 
1  foot  in  the  whole  length  of  oven.  Both  back  and  front  are  mova- 
ble and  have  swinging  doors,  which  are  in  two  sections,  and  built 
of  firebrick  of  special  design,  laid  in  iron  frames. 

"There  are  three  openings  on  top,  two  funnel  heads  and  one 
draft  stack  near  the  back  end  of  the  oven.  In  front  of  it  and  on 
a  level  with  the  floor  of  the  ovens  is  an  apron  of  stone  and  brick 
masonry,  8  feet  wide  and  running  the  entire  length  of  the  battery. 


166 


TREATISE  ON  COKE 


Four  feet  below  this  masonry  or  apron  is  another  piece  of  masonry 
7  feet  wide,  which  also  runs  the  entire  length  of  the  battery,  on 
which  the  truck  of  the  dinky  containing  the  machinery  for  drawing 
the  coke  is  located.  Still  farther  below  is  the  railroad  track,  on 
which  are  placed  the  cars  for  the  receipt  and  shipment  of  the  coke. 
At  the  rear  of  the  battery  is  another  track,  on  which  runs  a  car  used 
for  conveying  the  drag  from  oven  to  oven,  and  on  this  car  is  per- 
manently fixed  a  crab  for  pulling  the  drag  back  after  discharging, 
Fig.  13. 

"Twelve  tons  of  coal  are  charged  from  6-ton  larries,  through 
the  funnel  heads,  and  the  leveling  is  done  from  both  ends. 

"When  ready  to  draw,  the  doors  at  both  ends  of  the  ovens  are 
swung  open  and  an  iron  rod  passed  through  the  oven  over  the  top 
of  the  hot  coke,  and  attached  to  the  drag  at  the  rear.  The  hot  coke 


Mac/)//?ery /or  drawn?  Coke 


FIG.  13.     COKE  DRAWER 

is  thus  drawn  in  a  body  out  of  the  front  end  of  the  oven,  and  over 
a  screen  attached  to  the  dinky,  at  which  point  the  fire  is  quenched 
with  water  falling  from  a  tank,  situated  above  the  screen,  no  water 
whatever  being  thrown  into  the  oven.  From  the  screen  it  falls  in 
broken  pieces  to  the  railroad  car  below  and  is  ready  for  shipment." 
The  yield  is  practically  the  same  as  from  the  beehive  ovens 
under  skilful  management,  and  the  Duality  of  the  product,  so  far 
as  can  be  determined  by  analyses  and  observation,  is  fully  up  to 
the  standard.  I  regret  that  I  cannot  present  data  showing  its  rela- 
tion to  the  beehive  coke  in  furnace  practice,  but  the  conditions  of  con- 
sumption are  such  that  it  has  not  been  practicable  to  make  such  a 
test.  The  claim  for  economy  in  reducing  the  labor  in  making  coke  in 
this  oven  requires  more  data  to  define  the  exact  amount.  The  rela- 
tive original  costs  of  this  and  the  beehive  oven,  to  produce  a  given  out- 
put per  month,  with  the  cost  of  repairs  of  each  kind  of  oven,  should 
have  been  submitted  in  order  to  have  a  fair  comparison  of  merits. 


TREATISE  ON  COKE  167 

It  will  readily  appear  that  in  all  these  ovens,  with  admission  of 
air  through  doors,  or  by  special  ports,  the  true  principle  of  coking 
is  retained — freedom  of  the  coal,  by  the  shallow  charges,  to  develop 
the  best  physical  structure  in  coking,  as  the  pressure  of  these  coal 
charges  in  these  broad  horizontal  ovens  is  so  slight  as  not  to  mate- 
rially compress  the  fusing  mass  in  forming  the  cells  in  making  coke. 
On  the  other  side,  there  is  some  waste  by  the  admission  of  air  in 
burning  the  expelled  gases  in  the  crowns  of  the  ovens  above, -and 
in  contact  with  the  coking  coal. 

This  is  all  that  can  be  urged  against  the  use  of  these  types  of 
coke  ovens  in  the  manufacture  of  coke.  With  care  in  cooling  the 
coke,  especially  when  watered  in  the  oven,  a  product  is  obtained 
in  best  condition  for  affording  the  utmost  calorific  energy  in  metal- 
lurgical operations. 

Browney  Coke  Plant. — Desiring  to  learn  the  condition  of  the 
beehive  coke  oven,  in  the  celebrated  Durham  coke  district  in 
England,  and  to  be  advised  as  to  the  progress  of  the  introduction  of 
the  narrow  or  retort  coke  oven  there,  with  the  status  of  efforts  in  the 
saving  of  the  by-products  of  tar  and  sulphate  of  ammonia,  I  wrote 
Sir  Isaac  Lowthian  Bell,  the  eminent  authority  on  all  matters  con- 
nected with  the  iron  and  steel  industries,  who  kindly  sent  the  draw- 
ings, shown  in  Fig.  14,  of  the  Browney  colliery  coke  plant  of  Messrs. 
Bell  Brothers,*  with  the  following  note  covering  my  inquiries: 

ROUNTON  GRANGE,  Northallerton,  May  22,   1893. 
MY  DEAR  MR.  FULTON: 

Various  circumstances,  my  own  engagements  not  being  the  least,  have 
conspired  to  delay  my  reply  to  your  letter  of  10th  ult. 

I  enclose  the  tracing  of  our  own  ovens,  by  means  of  the  waste  heat  of 
which  we  supply  our  collieries  with  steam  power.  In  these,  by-products 
are  wasted,  as  you  no  doubt  will  see.  It  is  difficult,  I  may  say  impossible, 
to  give  a  categorical  reply  to  your  inquiry  in  respect  to  the  narrow  ovens 
in  which  combustion  in  the  ovenself  is  avoided  and  where,  in  consequence, 
ammonia  and  tar  escape  decomposition.  In  certain  districts,  even  in  England, 
they  are  successful,  the  difficulty  being  their  maintenance  in  good  repair. 

In  South  Wales  they  seem  to  do  very  well;  with  us,  in  the  county  of 
Durham,  and  in  Yorkshire,  the  reverse  has  frequently  been  the  result. 
My  own  opinion  is  that  the  richness  in  combustion  gas  lies  at  the  root  of 
the  evil,  the  consequence  being  an  elevation  of  temperature  in  the  outside 
flues  which  is  incompatible  with  stability. 

My  own  firm  has  spent  large  sums  in  pursuit  of  a  plan  of  obtaining 
ammonia,  etc.,  and  the  firm  of  Messrs.  Pease  and  Company  is  continuing 
the  process  with  perfect  success  as  regards  the  by-products;  but  they,  or 
their  customers,  find,  as  we  found,  the  coke  not  so  suitable  for  blast-furnace 
work  as  that  burnt  in  the  old-fashioned  beehive  oven. 

I  am  very  sorry  that  I  find  it  impossible  to  see  your  exhibition  at 
Chicago.  I  must  therefore  be  content  to  hear  what  others  have  to  say  on 
the  subject. 

With  my  kindest  regards  to  all  my  good  and  faithful  friends  in  Johns- 
town, believe  me  yours  faithfully,  I.  LOWTHIAN  BELL. 

*The  chimney  for  these  ovens,  the  base  of  which  is  shown  in  the  end 
elevation,  Fig.  14,  extends  80  feet  above  the  top  of  the  ovens,  and  is  battered 
1  in  27. 


168 


TREATISE  ON  COKE 


CE3 


s: 


TREATISE  ON  COKE  169 

I  enclose  a  letter  also  from  our  engineer,  Mr.  Steavenson. 

Mr.   Steavenson's    letter    reads  as  follows:     By  the    narrow    ovens,    I 

E  resume  Mr.  Fulton  means  those  which  are  discharged  by  ram  and  cooled 
y  water  outside;  this,  we  have  always  found,  causes  an  excess  of  moisture 
amounting  to  4  or  5  per  cent.,  whereas  with  the  round  oven  it  does  not 
exceed  the  half  of  1  per  cent.,  when  cooled  before  being  drawn. 

If  the  narrow  ovens  are  burned  close  so  as  to  produce  by-products,  it 
gives  a  solid  lumpy  material  which  works  badly  in  the  blast  furnace. 

Messrs.  Newton,  Chambers  and  Company,  of  Sheffield,  say  they  are 
successfully  drawing  off  the  by-products  from  the  floor  of  the  open  burning 
beehive  oven;  this  may  depend  on  their  having  an  open  free-burning  coal, 
but  we  have  not  yet  succeeded  in  doing  it  with  the  rich-burning  coal  of 
Durham,  and  when  we  get  64  per  cent,  of  good  coke  and  all  the  steam  which 
is  required  for  drawing  1,000  tons  per  day,  and  pumping  a  large  feeder  of 
water  from  600  feet,  we  seem  to  have  accomplished  a  fairly  satisfactory 
result.  A.  L.  STEAVENSON. 

From  the  arrangements  of  the  beehive  coke  ovens  of  the  Messrs. 
Bell  Brothers,  England,  it  will  be  seen  that  the  hot  gases  from  these 
ovens  are  conveyed  through  a  central  conduit  and  carried  under 
boilers,  affording  steam  for  winding  coal,  pumping  water,  and  other 
uses.  Similar  applications  of  the  waste  heat  of  coke  ovens  have 
been  made  in  Scotland  and  on  the  continent  of  Europe. 

Since  the  above  was  written,  very  commendable  progress  has 
been  made  in  England  and  Scotland  in  improving  the  beehive  coke 
ovens,  and  in  the  introduction  of  several  plans  of  the  retort  coke 
ovens  with  the  saving  of  the  by-products. 

Use  of  Waste  Gases  for  Steaming  at  Pratt  Mines,  Alabama. — In 

America,  these  waste  gases  have  been  utilized  at  a  few  plants  in  a 
similar  service — generating  steam.  Mr.  E.  Ramsay,  mining  engi- 
neer of  the  Tennessee  Coal,  Iron,  and  Railroad  Company,  describes, 
in  a  paper  read  before  the  Alabama  Industrial  and  Scientific 
Society,  the  method  in  use  at  the  Pratt  mines: 

"In  order  that  the  construction  and  mode  of  operation  of  the 
plants  now  in  operation  may  be  readily  understood,  I  have  prepared 
plans  of  one  of  the  plants  to  which  reference  will  be  made  in  this 
paper,  Fig.  15.  As  noted  heretofore,  the  ovens  from  which  the 
gases  and  heat  are  derived  were  built  some  years  ago  and  were  in 
operation  at  the  time  work  was  commenced.  The  first  part  of  the 
work  undertaken  was  the  construction  of  the  longitudinal  main 
flue,  which  is  cylindrical  in  section  and  placed  immediately  to  the 
rear  of  the  ovens.  A  few  ovens  were  blown  out  at  a  time,  and  as 
the  flue  was  built  and  connection  made  to  each  oven,  these  ovens 
were  again  put  in  blast  and  others  blown  out,  and  so  on  until  the 
flue  had  been  built  and  connections  made  to  the  entire  battery  of 
twenty-five  ovens.  This  main  flue  is  3  feet  6  inches  internal 
diameter,  has  4-inch  walls  on  bottom  half  and  9-inch  walls  on  top 
half,  and  is  built  of  firebrick  furnished  by  the  Bessemer  Firebrick 
Company,  of  Bessemer,  Alabama.  At  first  thought,  it  may  seem 
that  the  walls  are  too  light  for  a  flue  of  such  diameter,  but  when  one 
reasons  that  this  flue  is  cylindrical  in  shape,  which  gives  the  greatest 


170 


TREATISE  ON  COKE 


possible  strength  for  the  amount  of  material  used,  the  objection 
does  not  have  the  same  force.  At  all  events,  it  has  given  no 
trouble  except  on  two  occasions,  when  a  few  bricks  fell  out  of  the 
walls  and  into  the  flue  at  the  juncture  of  one  of  the  small  flues 
which  connect  it  with  the  ovens.  When  the  clay  and  earth  filling 
was  removed  from  the  rear  of  the  ovens  to  make  room  for  the 


main  flue,  it  was  found,  as  was  expected,  to  be  quite  hard  burned, 
and  especially  that  part  resting  on  the  oven  walls  proper,  which 
was  as  hard  burned  as  an  ordinary  red  brick.  This  hard  material 
was  nicely  cut  out  to  a  section  equal  to  the  half  circle  of  the  exter- 
nal diameter  of  the  flue,  the  bottom  half  of  which  was  laid  in  it, 
using  the  cut-out  section  as  a  form  and  a  loamy  clay  as  mortar. 


TREATISE  ON  COKE  171 

The  upper  half  of  the  flue  was  then  laid,  using  the  ordinary  wood 
centers,  which  were  moved  along  as  the  flue  was  completed.  Over 
the  upper  half  of  the  flue,  a  layer  of  about  6  inches  thick  of  well- 
puddled  clay  was  put  on,  which,  when  the  heat  was  turned  on, 
was  burned  into  the  hardness  of  a  red  brick.  This  plan  was  adopted 
as  a  cheap  means  of  reenforcing  and  adding  strength  to  the  walls 
of  the  flue  and  making  it  so  that,  if  a  brick  or  two  did  fall  out,  it 
would  be  quite  probable  that  the  flue  would  continue  to  do  duty 
until  a  convenient  time  for  making  repairs  could  be  had.  In  both 
of  the  instances  where  the  flue  gave  way,  work  was  continued  for 
several  days  before  repairs  were  made.  As  is  shown  by  the  plan, 
in  transverse  and  longitudinal  sections,  the  main  flue  is  built  in 
contact  with  the  rear  walls  of  the  ovens  and  a  connection  is  made 
to  each  oven  at  the  point  of  contact  by  a  cylindrical  firebrick  flue 
12  inches  in  diameter  and  about  20  inches  long. 

"  There  are  two  boiler  plants  of  the  design,  size,  and  construction 
shown  in  plan  in  operation  at  Pratt  mines,  and  each  receives  the 
heat  and  gases  from  its  individual  battery  of  12-foot  bank  beehive 
ovens  of  the  usual  American  construction.  Each  plant  consists 
of  two  batteries  of  46"  X  26'  boilers,  with  two  16-inch  flues  each, 
and  is  situated  midway  and  to  the  rear  of  the  ovens  in  such  a  position 
that  the  transverse  center  line  which  passes  through  the  center 
of  the  thirteenth  oven,  counted  from  either  end,  is  also  the  center 
line  of  the  boiler  plant.  The  boilers  were  placed  in  the  center  of 
the  bank  of  ovens  for  the  reason  that  the  closer  they  were  placed 
to  the  ovens  the  less  the  distance  would  be  which  the  gases  would 
have  to  travel,  and  consequently  the  less  would  be  the  loss  of 
the  initial  heat  of  the  gases  by  radiation.  To  illustrate:  the 
boilers  might  be  placed  so  far  from  the  ovens  as  to  cause  the  gases 
to  part  with  all  the  initial  oven  heat  before  arriving  at  the  boilers, 
and  in  such  a  case  the  benefit  derived  would  be  alone  in  the  com- 
bustion of  the  gases  at  the  boilers,  with  the  proper  admixture  of 
air,  in  a  manner  similar  to  the  burning  of  gases  from  the  blast 
furnaces  under  boilers  and  in  hot-blast  stoves.  This  being  the  case, 
it  is  apparent  that,  unless  the  conditions  will  not  admit  of  it,  the 
boilers  should  be  placed  as  close  to  the  ovens  as  possible.  The 
boiler  settings,  as  will  be  seen  from  the  drawings,  are  of  the  ordinary 
type,  with  the  boiler  fronts  and  grate  bars  omitted.  To  have  used 
grate  bars,  in  order  to  allow  of  hand  firing  with  coal,  would  have 
complicated  the  plant  to  an  extent  which  the  benefits  to  be  derived 
would  not  have  warranted.  As  noted  in  a  previous  portion  of  this 
paper,  grate  bars  were  used  in  the  first  experimental  plant  erected 
at  Pratt  mines,  and  in  that  case  they  were  rapidly  destroyed  by  the 
incandescent  gases  passing  over  them.  To  have  obviated  this 
trouble  it  would  have  been  necessary  to  admit  the  gases  back  of 
the  grate  bars,  and  in  such  a  case  that  part  of  the  boiler  immediately 
over  the  bars  would  have  been  practically  dead  space ;  or  a  furnace 
might  have  been  built,  to  one  or  both  sides  of  the  boilers,  in  such 


172  TREATISE  ON  COKE 

a  manner  as  to  admit  the  heat  and  gases  at  the  same  point  as  they 
are  now  admitted  in  the  plant  described  in  this  paper. 

"  In  order  that  each  battery  might  be  worked  separately,  or  both 
at  one  time,  an  independent  flue  from  the  main  flue  and  discharging 
under  the  battery  is  provided,  as  shown  in  the  plan,  and  in  each 
of  these  branch  flues,  which  are  of  the  same  diameter  as  the  main 
flue,  a  damper  was  placed  in  the  first  plant  built;  but  after  working 
practically  for  several  months  it  was  found  to  be  almost  unneces- 
sary, as  the  opening  of  the  breeching  and  cleaning  doors  at  once 
stops  the  draft  and,  consequently,  the  flow  of  gases,  and  if  the 
shut-down  was  to  be  for  any  length  of  time,  it  would  be  an  easy 
matter  to  close  one  of  the  flues  with  a  temporary  brick  wall,  such 
as  is  used  in  closing  coke-oven  doors  at  each  drawing.  That  it 
is  only  a  matter  of  a  few  minutes'  work  to  open  these  doors 
and  take  off  the  oven  dampers  has  been  demonstrated  on  several 
occasions  when  it  was  desired  to  stop  the  flow  of  gas  and  heat 
to  the  boilers.  In  fact, "this  can  be  done  as  expeditiously  almost 
as  a  damper,  large  and  unwieldy  as  it  would  necessarily  be,  could 
be  manipulated. 

"The  amount  of  steam-actuated  machinery  at  this  mine,  shaft 
No.  1,  is  very  large,  and  requires  a  great  amount  of  steam  for  its 
operation.  Before  the  utilization  of  the  waste  heat  and  coke-oven 
gases  in  the  making  of  steanij  this  plant  used  monthly  about 
1,500  tons  of  coal,,  or  7^  per  cent,  of  the  entire  output  of  the  mine 
for  boiler  use.  This,  at  $1  per  ton,  represented  a  monthly  loss  of 
$1,500  for  boiler  coal,  or  about  7^  cents  per  ton  of  coal  on  the 
entire  output.  So  long  as  the  selling  price  of  coal  was  reasonably 
remunerative,  this  large  outlay  for  boiler  fuel  was  not  felt  so  much, 
but  as  the  selling  price  constantly  became  less  and  less,  it  was 
imperative  that  something  should  be  done.  Then  work  was  com- 
menced on  the  boiler  plants  at  the  bank  coke  ovens,  and  so  suc- 
cessful has  been  their  operation  that  the  coal  used  at  the  old  boilers 
has  been  reduced  to  300  tons  per  month.  When  the  amount  of 
labor  used  at  the  coal-fired  boilers  for  firemen  and  ash  wheelers, 
together  with  the  expense  of  grate  bars  and  general  wear  and  tear 
is  considered,  it  is  no  exaggeration  to  say  that  the  coke-oven 
boilers  have  effected  a  monthly  saving  of  $1,500,  or  $18,000  per 
annum.  By  utilizing  the  gas  from  another  block  of  twenty-five 
ovens,  the  entire  plant  could  be  supplied  with  steam  without  using 
any  coal  whatever,  except  a  little  on  Monday  mornings,  when 
the  ovens  are  cold  from  standing  over  Sunday;  and  even  this 
could  be  obviated  by  drawing  and  charging  a  few  of  the  ovens 
on  that  day." 

From  the  evidence  of  the  economy  in  these  methods  of  utilizing 
the  waste  gases  from  plants  of  beehive  coke  ovens  in  affording  heat 
for  generating  steam,  it  is  evident  that  it  will  be  well  to  consider 
these  examples  on  the  lines  of  economy,  especially  in  erecting 
new  plants  of  coke  ovens. 


TREATISE  ON  COKE 


173 


The  Ramsay  Patent  Beehive  Coke  Oven. — The  design  of  the  Ram- 
say oven  is  to  secure  a  hard-bodied  coke,  to  prevent  the  production 
of  black  ends  in  the  coke,  and,  by  means  of  its  bottom  flues  affording 
increased  heat,  to  coke  the  dry  coals  or  coals  low  in  volatile  matter. 
The  high  temperature  of  this  oven  assures  a  hard-bodied  coke,  which 


(C) 

-Secf/0/? ABCD 


wss 

^^^^^^^^^^^.^v":>:^:>;'^^^^ 
'(d) 


FIG.  16.     RAMSAY  PATENT  BEEHIVE  OVEN 


is  most  desirable  for  use  in  blast-furnace  operations,  as  it  resists  dis- 
solution, in  its  downward  passage  in  the  furnace,  from  the  ascending 
hot  carbonic-acid  gas.  This  hard-bodied  coke  is  secured  by  the  use 
of  all  the  gas  evolved  in  coking  and  burned  in  the  oven  flues. 

Fig.  16  shows  the  detail  of  this  oven  as  built  at  Byrendale 
Coke  Works,  in  Elk  County,  Pennsylvania;  (a)  is  a  plan  showing 
the  arrangement  of  the  flues;  (6),  (c),  and  (d)  are  cross-sections. 


174 


TREATISE  ON  COKE 


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TREATISE  ON  COKE 


175 


The  following  is  the  explanation  of  the  reference  letters  used 
in  connection  with  the  drawings,  Fig.  16,  showing  the  construction 
of  the  Ramsay  patent  beehive  oven:  a,  body  of  oven;  b,  front  wall 
of  oven;  c,  wall  between  center  flue;  d,  stack  in  rear  of  oven; 
e,  trunnel  ring;  /,  oven  door;  g,  top  tile  bottom  of  oven;  h,  damper 
in  stack;  i,  j,  composition  air-tight  packing;  k,  bottom  tile  of 
oven ;  /,  two  horizontal  flues  extending  from  front  of  oven  to  stack 
at  back  of  oven;  m,  stack  in  rear  of  oven;  n,  covering  of  the  double 
flues  /;  o,  inlet  front  flues  from  bottom  of  outlet  flues;  p,  inlet  back 
flues  from  bottom  of  outlet  flues;  q,  r-,  s,  t,  u,  v,  w,  radiating  flues 
under  oven;  x,  pillars  between  flues  under  oven;  y,  four  inlet  flues 
from  oven  to  flues;  z,  top  covering  tile  on  top  of  flues. 

Mode  of  Operation. — Coal  is  charged  the  same  as  in  a  common 
beehive  oven  at  e  and  leveled,  the  opening  e  and  door  /  are  closed, 
and  the  damper  h  is  partially  closed  when  ignition  takes  place. 
/  and  h  are  regulated  as  occasion  demands.  The  operation  of  the 
flues  is  as  follows:  the  gases  generated  in  the  oven  enter  flues  y, 
descend  o,  radiate  through  s,  q,r,u,  and  t  into  parallel  flues  /,  and 
escape  through  the  stack  m\  when  the  oven  is  burned  oft",  the  coke 
is  watered  in  the  oven  and  then  drawn  by  hand  in  the  manner 
commonly  employed  in  drawing,  the  ordinary  beehive  oven. 

COMPARATIVE    AVERAGE    ANALYSES    OF  COKE    MADE    IN    RAMSAY 
AND  COMMON  BEEHIVE  OVENS 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Ramsay  
Beehive    .      ... 

.02 

.17 

.75 
1  58 

89.28 
87  53 

9.95 

10  72 

1.05 
1    12 

.024 

025 

NOTE. — These  analyses  were  made  by  the   Metallurgical   Laboratory, 
545  Liberty  Avenue,  Pittsburg,  Pennsylvania. 

Comparison  of  Wages. — Ramsay. — Charging,  .05;  leveling,  .12; 
drawing,  .99;  total,  $1.16.  The  average  charge  per  drawing  is 
6.645  tons,  then  $1.16  -=-  6.645  =  17.5  cents  per  ton. 

Beehive. — Charging,  .05;  leveling,  .11;  drawing,  .77;  total,  $.93. 
Average  charge  per  drawing  is  3.55  tons,  then  .93  -r-  3.55  =  26.2 
cents  per  ton,  a  saving  of  8.7  cents  per  ton  in  favor  of  the 
Ramsay  oven. 

In  considering  the  relative  economy  of  operating  different  types 
of  ovens,  the  first  cost  is  an  important  item  which  must  be  taken 
into  account. 

The  following  is  an  estimate  of  materials  and  cost  of  the  beehive 
and  Ramsay  coke  ovens:* 

*The  relative  work  of  the  beehive  and  Ramsay  ovens,  with  all  other 
matter,  has  been  furnished  by  Mr.  Geo.  S.  Ramsay. 


176  TREATISE  ON  COKE 

STATEMENT  OF  MATERIAL  AND  COST  FOR  THE  BEEHIVE  OVEN 

3,100  crown  brick  at  $32 $  99  20 

1,800  liners  at  $32 57  60 

1  set  of  fronts  at  $1 1  per  set 1 1 . 00 

900  red  brick  at  $9 8.10 

500  red  brick  for  ring  wall  at  $9 4 .  50 

118  floor  tile  at  $95 11.21 

1  trunnel  head  at  $3 3 . 00 

1  trunnel-head  ring  at  $3 3 . 00 

Frame 6 . 00 

Labor 239.21 

Extra  labor  and  supplies  not  mentioned  above 59 .  70 

Total..  ..$502.52 


MATERIAL  NECESSARY  FOR  ONE  RAMSAY  PATENT  COKE  OVEN 

FIREBRICKS 

3,000  9-inch  quartzite  bricks  for  bottom  flues 
2,500  9-inch  quartzite  bricks  for  side  flues 

5,500  9-inch  Q.  T.  Z.  at  $21  per  M $115.50 

1,900  12-inch  Juniata  liners  at  $35 66. 50 

2,900  12-inch  Q.  T.  Z.  crown  bricks  at  $45 130. 50 

190  8"  X  3"  X  18"  Q.    T.    Z.    covering   and   bridge   tiles    at    13 

cents 24 . 70 

20  6"  X  6"  X  18"  Q.  T.  Z.  blocks  at  20  cents 4. 00 

130  12"  X  12"  X  2f"  floor  bricks  at  10  cents 13.00 

56   12-inch  Q.  T.  Z.  special  arch  bricks  for  flues  at  20  cents 11 . 20 

8  Juniata  jamb  blocks  at  $2.50 20. 00 

2  Juniata  R.  and  L.  skews  at  $2 4 . 00 

5  Juniata  arch  bricks  at  $2 10 . 00 

1  trunnel  ring 3 . 00 


Total $402. 40 

RED   BRICKS 

1,000  bricks  for  bottom  ring  1 

3,500  bricks  for  chimney         \  K  AM    +  *u\  a   KA  ™ 

700  bricks  for  pier  f 5'400  at  $1° $  54.00 

200  bricks  around  door        J 

FIRECLAY BRICKLAYING   AND   ASBESTOS 


10  tons  of  fireclay,  including  freight,  at  $7 $  70 

7  sheets   of   asbestos    44"  X  44"  X  f",    360    pounds   at 

5  cents 18 

Bricklayer  and  helpers 90 

178.00 

STONEWORK EXCAVATION  AND   FILLING 

40  perches  of  stone  work  at  $4 $160 

10  yards  of  excavation  at  $1 10 

45  yards  of  filling  at  $1 45 

1  capstone  for  pier 1 

216.00 


v\ 


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. 


3  "Concrete-^ 


Ccke  Gas  inlet - 

Super  Heated  Steam  or  Air  Inlet - 
COKE  CONVEYOR  AND  QUENCHING 


(a) 


17303— v 


FIG.  17.     DAUBE'S 


-''iv?  ^r-0'«>»>;j-j^*    *o*     ~    "  ~  \*' Concrete  Under  J  |       ! "'  rj" 

:li--TV'*-»'->'.k>i^J Fire  Brick  Floor    j  j  !  !   I 

C'latnbep                "W  --••^•->i-"V'  !  !^ 

k — aV-^ 


tion 


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-DRAFT  COKE  OVEN 


TREATISE  ON  COKE  177 

IRONWORK 

4  6-inch  I  beams  at  6  feet  long — 24 

feet  at  15  pounds 360  pounds 

1  20'  X  9"  girder  rail  with  distance 

pieces 900  pounds 

1  cast-iron  door  frame 360  pounds 

1  cast-iron  cover-plate 50  pounds 

4  wrought-iron  anchors 30  pounds 

1700  pounds  at  3  cents         51 . 00 
Total, $901 . 40 

Mr.  Ramsay  estimates  that  under  ordinary  conditions  this  oven 
can  be  built  for  $675.  Under  normal  conditions  the  beehive  oven 
costs  $250  to  $300. 

Daube's  Economic  Down-Draft  Coke  Oven.* — The  accompany- 
ing illustrations,  Fig.  17,  show  the  details  of  a  coking  oven  invented 
by  Oscar  Daube,  of  New  York,  having  for  its  object  an  improvement 
in  the  quality  of  by-product  coke.  The  oven  is  built  on  a  beehive 
plan.  Under  each  one  is  located  a  combustion  chamber  operated 
under  forced  draft  with  coke-oven  gas  or  fuel.  This  results  in 
coking  from  the  bottom  up,  while  the  waste  gases  from  the  com- 
bustion chamber  pass  up  the  rear,  entering  the  oven  above  the  coke 
bed  under  pressure,  which  causes  the  coking  to  take  place  from  the 
top  down  and  'from  rear  to  center.  The  gases  generated  in  the 
coking  process  are  drawn  through  flues  that  pass  down  the  sides 
and  also  under  the  floor  of  the  ovens,  giving  off  their  radiant  heat 
on  their  outward  passage  to  the  coke  in  the  oven.  It  will  thus  be 
seen  that  the  coking  process  takes  place  from  the  bottom  up,  top 
down,  and  from  sides  to  center.  The  process  is  claimed  to  be  rapid, 
completing  in  24  hours  a  charge  of  6^  long  tons.  The  coke  obtained 
is  said  to  be  of  first-class  quality,  running  from  88  to  92  per  cent, 
carbon  and  yielding  67  to  72^  per  cent,  of  coke. 

The  manner  of  withdrawing  the  gases  at  the  side  and  bottom 
of  the  oven  has  for  its  object  the  decomposition  of  the  heavy  hydro- 
carbons. These,  coming  in  contact  with  the  incandescent  coke, 
decompose  on  their  outward  passage,  adding  a  percentage  of  carbon 
to  the  coke;  hence,  the  large  yield  of  coke  per  ton  of  coal.  The 
yield  of  tar  is  correspondingly  reduced  from  12  to  14  gallons  per 
.  ton  to  from  4  to  5  gallons.  The  quantity  of  gas  recovered  is  approx- 
imately 5,000  cubic  feet  per  ton,  the  balance  being  used  for  heating 
the  ovens.  This  recovery  compares  favorably  with  the  amount  now 
being  obtained  by  other  by-product  coke  ovens.  The  ammonia 
saved  amounts  to  from  25  to  35  pounds  per  ton  of  coal,  depending, 
of  course,  on  the  percentage  of  nitrogen  in  the  coal  coked.  The 
above  results  are  on  a  basis  of  a  good  coking  coal,  capable  of  coking 
by  any  process.  There  are,  however,  large  areas  of  so-called 


*Engineering  and  Mining  Journal,  November,  1902. 


178  TREATISE  ON  COKE 

non-coking  or  poor-coking  coal  that  up  to  date  none  of  the  present 
coke  ovens  have  successfully  coked. 

The  economic  down-draft  coking  process  has  been  developed 
on  the  opinion  held  by  Sir  I.  Lowthian  Bell,  and  others,  that  the 
cause  of  the  poor-coking  or  non-coking  qualities  of  coals  lay  in  the  fact 
that  they  are  low  in  disposable  hydrogen,  and  which  in  slow  ovens 
volatilizes  before  the  coking  stage  is  reached.  This  theory  is 
claimed  to  have  been  proved  correct  in  this  process,  which,  owing  to 
its  ability  to  generate  a  high  uniform  heat  at  the  beginning  of  the 
coking  operation,  brings  about  the  fusing  or  coking  stage  before 
the  disposable  hydrogen  is  volatilized.  The  inventor  states  that  a 
number  of  western  coals  heretofore  considered  non-coking  have 
been  successfully  coked  by  the  economic  process.  The  cost  of 
these  ovens,  independent  of  by-product  recovery  plant,  is  said  to 
be  only  slightly  higher  than  that  of  the  ordinary  beehive  oven. 


IMPROVED  HEMINWAY  PROCESS* 

This  improvement  relates  to  the  method  of  coking  in  a  beehive 
oven,  and  has  for  its  object  not  only  the  production  of  a  good 
sound  metallurgical  coke  from  so-called  non-coking  coals,  but  also 
the  improvement  of  the  practice  of  coking  the  well-known  grades 
of  coking  coal. 

It  is  generally  admitted  that  a  good  coking  coal  must  contain 
from  20  to  30  per  cent,  of  volatile  matter;  it  must  be  low  in  ash  and 
sulphur,  and  when  subjected  to  a  coking  heat  must  fuse  or  become 
pasty,  and  while  in  this  pasty  condition  it  must  give  up  its  vola- 
tile matter  in  such  form  that  during  its  evolution  from  the  pasty 
mass  of  coal  it  will  push  a  number  of  carbon  particles  together  so 
as  to  form  strong  cell  walls,  separated  from  one  another  by  pores. 

Suppose  that  the  volatile  matter  in  a  coal  is  over  40  per  cent. ;  it 
naturally  follows  that  one  must  change  or  modify  the  ordinary 
practice  followed  in  beehive  ovens,  because  the  greater  volume  of 
volatile  matter  would  increase  the  size  of  the  pores  and  thus  weaken 
the  carrying  strength  of  the  coke,  unless  the  strength  of  the  cell 
walls  was  correspondingly  increased;  that  is,  provided  that  the 
rate  of  evolution  of  volatile  matter  was  the  same  in  both  cases. 
But  suppose  that  the  volatile  matter  in  the  latter  case  is  evolved 
at  a  much  greater  rate,  might  not  this  rapid  evolution  have  a  ten- 
dency to  cause  more  pressure  in  the  oven  and  thus  close  the  pores ; 
in  fact,  might  it  not  even  change  the  shape  and  regularity  of  the 
cells  as  well,  thus  producing  a  coke  too  dense  and  one  that  would 
not  absorb  the  hot  gases  in  the  blast  furnace  under  usual  conditions? 
I  consider  it  possible  to  obtain  good  results  from  coke  whose  cell 
structure  is  not  exactly  similar  to  the  recognized  form.  I  also 


*Dr.  R.  S.  Moss  in  Mines  and  Minerals,  April,  1901. 


TREATISE  ON  COKE  179 

consider  it  possible  to  alter  the  cell  structure  of  a  coke  at  will  during 
the  time  of  coking  by  an  intelligent  manipulation  of  the  pressure 
in  the  oven,  which  can  very  easily  be  accomplished  by  the  use  of 
my  improved  method  of  coking. 

It  is  well  known  that  the  fusibility  of  a  coal  does  not  depend 
on  the  volume  of  volatile  matter  present  in  the  coal ;  however,  the 
greater  the  fusibility  of  a  coal,  the  greater  is  the  range  to  which  it 
lends  itself  for  easy  change  of  the  size  and  arrangement  of  its  cells ; 
but  what  effect  does  this  have  on  the  carbon  regarding  its  efficiency 
for  blast-furnace  work?  Suppose  that  I  produce  a  very  porous 
and  a  very  dense  coke  from  the  same  coal,  does  it  not  follow  that, 
although  the  percentage  of  fixed  carbon  is  the  same  in  both  cases, 
the  efficiency  under  the  same  conditions  in  a  blast  furnace  will 
vary  between  wide  limits;  but  is  this  the  fault  of  the  material  or 
the  method  of  operating  the  blast  furnace?  The  same  heat  units 
are  represented  in  both  the  porous  and  the  dense  coke,  they  are 
both  strong  enough  to  bear  the  usual  burden  of  ore,  and  yet  the 
proportion  of  coke  to  ore  is  very  much  greater  in  one  case  than  in 
the  other;  this  assumes  that  carbon  in  all  its  various  forms,  as 
found  in  coke,  will  develop  the  same  efficiency.  But  does  it?  If 
oxidized  directly  to  carbonic  acid  its  efficiency  must  necessarily  be 
the  same,  but  as  a  matter  of  fact  two  cokes  of  exactly  similar 
analyses  give  different  efficiencies ;  what  is  the  cause  ?  Clearly  this 
can  be  readily  ascertained  by  making  a  simple  analysis  of  the 
gases  escaping  from  the  blast  furnace.  It  will  be  found  that  the 
ratio  of  carbonic  acid  to  carbon  monoxide  is  higher  in  the  gases 
from  the  coke  showing  the  highest  efficiency,  and  vice  versa;  but 
why  should  one  coke  give  a  higher  efficiency  than  another  where 
the  fixed  carbon  in  both  is  equal  ?  Obviously,  oxidation  of  the  fixed 
carbon  is  not  equal,  and  as  oxidation  depends  on  the  air  supply, 
all  other  conditions  being  the  same,  the  pressure  of  air,  or  the  vol- 
ume, or  both,  must  be  changed;  but  here  again  is  a  limit  to  which 
we  can  either  increase  or  decrease  pressure,  or  volume,  or  both,  to 
advantage ;  but  as  the  limit  lies  within  very  wide  margins  it  will 
be  found,  in  practice,  that  equally  good  results  may  be  obtained 
with  either  a  dense  or  a  porous  coke,  provided  that  they  both  hold 
the  burden,  by  manipulating  the  air  supply  either  as  regards  pres- 
sure or  volume  to  suit  the  coke. 

Let  us  return  to  our  coke  ovens.  When  I  took  charge  of  the 
Universal  Fuel  Company 's  plant  I  found  a  battery  of  four  experi- 
mental ovens  in  operation  under  the  Heminway  process;  to  these 
ovens  a  by-product  plant  had  been  attached;  the  arrangement 
was  such  that  the  gas  was  taken  off  from  the  t runnel  head,  thence 
to  a  small  hydraulic  main  placed  at  some  considerable  distance 
from  the  ovens,  thence  through  a  Root  exhauster  to  a  Pelouze  & 
Audouin's  condenser,  from  there  through  a  scrubber,  and  thence 
measured  through  a  proportional  meter  to  a  purifier  and  on  to  the 
holder.  I  found  this  arrangement  both  useless  and  dangerous. 


180  TREATISE  ON  COKE 

Good  hard  coke  was  being  made  from  western  coals  and  everything 
appeared  favorable  as  regards  the  matter  of  coking. 

By  the  Heminway  process,  air,  hot  or  cold,  was  blown  into  the 
oven  just  above  the  top  of  the  coal.  If  the  oven  was  rather  cold, 
or  the  charge  did  not  readily  ignite,  hot  air  was  used;  the  air 
was  heated  to  600  or  700°  F.  by  being  passed  through  firebrick 
checker  work  in  a  furnace  external  to  the  oven,  thus  aiding  combus- 
tion. The  amount  or  volume  of  air,  either  hot  or  cold,  was  not 
regulated  in  proportion  to  the  amount  or  volume  of  the  volatile 
matter  that  was  given  off  from  the  coal;  hence,  the  object  aimed 
at  was  not  gained  at  all  times.  If  an  oven  appeared  hot,  the  air 
was  put  in  and  the  oven  was  blown  continuously,  resulting  in 
nothing  more  than  further  heating  the  air,  which,  passing  off  from 
the  trunnel  head,  carried  considerable  heat  from  the  brickwork, 
hence  cooling  down  the  oven  so  much  that  after  the  expiration  of 
a  few  hours  the  oven  was  very  much  cooler  than  when  charged. 
The  coal  did  not  coke,  and  the  inevitable  result  of  an  oven  making 
breeze  and  not  coke  was  obtained.  This  had  been  the  case  time 
and  again;  the  cause  assigned  by  those  in  charge  was  deterioration 
of  the  coal  used,  due  to  the  weather,  or  perhaps  it  might  be  the 
effect  of  a  few  days  longer  on  the  road  from  the  mine  to  the  works, 
or  it  might  have  got  wet  in  transit,  etc. ;  be  that  as  it  may,  while 
we  all  know  that  coal  does  deteriorate  if  exposed  to  atmospheric 
changes,  yet  I  have  never  heard  of  any  coal  undergoing  such 
remarkable  changes  in  such  a  short  time. 

It  has  been  found  that,  while  the  Heminway  method  does 
increase  rapidity  of  combustion,  the  rate  of  coking  is  seriously  dis- 
turbed throughout  the  mass  of  coal;  for  instance,  the  top  layer  of 
coal  is  coked  long  before  the  bottom,  hence,  at  the  high  temper- 
ature maintained  by  this  method,  the  coke  or  carbon  in  the  upper 
part  of  the  oven  is  burned  while  waiting  for  the  lower  layer  to 
coke.  This  is  as  might  be  expected;  coal  and  coke  are  bad  con- 
ductors of  heat,  hence  the  rate  of  heat  penetration  throughout  the 
mass  of  coal  is  disturbed.  The  upper  layers  coke  rapidly  without 
giving  a  corresponding  increase  to  the  lower  layers. 

Let  us  assume  the  normal  conditions  found  in  beehive  ovens: 
5  to  7  tons  of  coal  are  charged  into  the  oven,  the  coal  is  leveled  off 
and  the  door  walled  up,  coking  takes  place  in  the  usual  way  and 
the  oven  is  drawn,  we  will  say,  in  48  hours;  black  ends  are  noticed 
on  the  bottom;  therefore,  the  coal  has  not  been  thoroughly  coked. 
If  a  sample  of  this  coke  is  taken  from  top  to  bottom,  we  shall  find 
that  the  volatile  matter  will  increase  from  above  downwards.  Now 
suppose  that  this  same  oven  is  attached  to  the  Heminway  process, 
again  charging  the  same  amount  of  coal — in  fact  with  all  conditions 
remaining  the  same — hot  or  cold  air  or  both  are  blown  into  the 
oven  as  deemed  best  under  the  circumstances,  so  that  complete 
combustion  takes  place  inside  the  oven;  it  naturally  follows  that 
the  temperature  of  the  oven,  at  least  the  space  within  the  area 


TREATISE  ON  COKE  181 

of  combustion,  will  increase  at  a  much  quicker  rate  than  in  the 
first  case;  hence,  all  other  conditions  remaining  the  same,  it  follows 
as  a  matter  of  course  that  the  increased  disproportion  of  heat 
distribution  in  the  latter  case  must  tend  to  set  up  an  unequal  rate 
of  coking  throughout  the  mass.  Supposing  that  the  oven  is  drawn 
just  as  soon  as  the  top  is  well  coked,  the  yield  of  coke  will  be  high, 
yet  it  will  vary  in  hardness  and  amount  of  volatile  matter  from 
above  downwards,  showing  large  black  ends,  practically  nothing 
but  fused  coal  on  the  bottom;  then  again,  if  we  continue  to  coke 
until  the  whole  of  this  volatile  matter  has  been  eliminated  and  the 
coal  is  thoroughly  coked  to  the  bottom,  we  shall  find  our  yield 
much  less  than  the  loss  of  volatile  matter  above  would  indicate, 
due,  in  this  case,  to  the  coke  having  been  consumed  on  top.  This 
teaches  that  the  ideal  coke  oven  must,  if  possible,  be  evenly  heated; 
it  must  evenly  maintain  that  heat  so  that  the  whole  mass  may  be 
completely  coked,  as  nearly  as  possible  at  one  and  the  same  time. 
If  our  material  were  a  good  conductor  of  heat  the  problem  would 
be  very  much  easier,  but  as  we  must  depend  on  the  heat  radiated 
from  the  firebrick  walls  and  bottom  of  our  oven,  it  takes  consider- 
able time  before  that  heat  and  the  heat  of  combustion  combined 
penetrate  through  the  mass  of  coal;  this  in  a  beehive  oven;  in  a 
closed  oven  the  trouble  is  not  exactly  the  same,  as  this  latter 
method  is  one  of  distillation  by  means  of  a  furnace  external  to  the 
oven.  To  overcome  the  difficulties  met  with  in  the  Heminway 
process  I  have  made  a  number  of  improvements,  which  are  herein 
set  forth  and  discussed. 

Instead  of  blowing  air  direct  from  an  opening  having  the  exact 
diameter  of  the  pipe  through  which  it  is  conveyed,  I  enlarge  the 
exit  by  making  it  elliptical  in  shape,  raised  slightly  on  the  lower 
side  instead  of  horizontal,  thus  blowing  the  air  in  a  slightly  upward 
direction  in  the  oven  and  at  a  sufficient  height  above  the  mass  of 
coal  to  protect  combustion  of  the  fixed  carbon,  by  a  cushion  or 
layer  of  volatile  matter  between  the  coal  and  the  air  supply;  at  a 
point  3  feet  at  least  from  the  center  of  the  air  exit  I  add  a  second 
air  supply  also  elliptical  in  shape  and  placed  almost  in  a  horizontal 
plane,  thus  completing  combustion  of  the  volatile  matter  that 
escaped  the  lower  supply  of  air.  It  is  obvious  at  once  that  the 
form  of  my  exit  will  insure  a  better  and  more  even  mixture  of  air 
and  combustible  gas  than  when  the  exit  is  round.  It  prevents  cut- 
ting or  channeling  of  the  volatile  matter  and  gives  a  better  diffusion ; 
then  again,  it  is  well  known  that  to  obtain  complete  combustion  a 
considerable  excess  of  air  is  required;  hence,  if  we  depend  entirely 
on  one  air  supply,  a  considerable  volume  of  inert  nitrogen  must 
be  thrown  into  the  oven,  thus  absorbing  heat  and  carrying  it  off 
at  the  trunnel  head.  If  complete  combustion  is  not  obtained, 
a  large  amount  of  combustible  volatile  matter  will  pass  out  of  the 
trunnel  head  and  be  consumed  in  the  open  air  without  giving  any 
heat  to  the  brickwork  in  the  oven.  By  adding  a  secondary  air 


182  TREATISE  ON  COKE 

supply  it  does  not  become  necessary  to  blow  as  much  air  into  the 
oven  from  the  lower  pipe.  Combustion  of  part  of  the  volatile 
matter  takes  place ;  the  heat  produced  by  this  combustion  is  trans- 
ferred to  the  whole  of  the  gases;  hence,  the  unconsumed  volatile 
matter  reaches  the  secondary  air  supply  at  a  higher  temperature 
than  would  otherwise  be  the  case;  hence,  such  an  excess  of  air  is 
not  required  to  obtain  complete  combustion  as  is  the  case  with  only 
one  air  supply,  and  the  whole  of  the  combustible  matter  is  con- 
sumed inside  the  oven,  thus  preventing  loss  of  heat  due  to  combus- 
tion on  the  outside  of  the  oven.  This  is  all  very  well  so  far  as  it 
goes,  yet  it  alone  only  increases  the  disproportion  of  rate  of  coking 
throughout  the  mass  of  coal  in  the  oven,  and  hence  aggravates 
rather  than  lessens  the  trouble  met  with  in  the  Heminway  process 
of  coking;  for,  with  this  increased  heat  above  the  coal,  the  top  layer 
of  coal  is  coked  much  more  quickly  than  in  the  Heminway  process, 
and  even  long  before  the  coal  on  the  bottom  of  the  oven  has  given 
off  its  volatile  matter;  hence,  we  must  either  draw  an  oven  with 
coal  on  the  bottom  not  coked  at  all,  or  we  must  run  it  until  coked, 
when  the  fixed  carbon  on  the  top,  or  rather  the  coke,  is  being  con- 
sumed and  the  top  is  ashed  over,  reducing  our  yield  very  seriously, 
as  well  as  increasing  the  percentage  of  ash;  therefore,  one  can  see 
that  this  improvement  in  itself  is  useless.  To  overcome  this  diffi- 
culty I  have  built  a  flue  from  the  inside  of  the  oven  just  below 
the  trunnel  head,  carrying  it  down  the  outside  of  the  oven  and 
under  the  bottom,  starting  near  the  front  of  the  oven  and  continu- 
ing along  the  bottom  to  the  back,  and  again  passing  outside  to  a 
main  flue  built  between  the  ovens,  where  the  gases  may  be  utilized 
for  raising  steam,  and  thence  to  a  chimney  discharging  into  the 
outer  atmosphere.  I  have  built  twelve  flues  under  the  oven,  and 
thus  equalized  the  heat  from  front  to  back;  the  front  being  the 
coolest  part  of  the  oven  in  a  battery  built  back  to  back  decided 
my  taking,  or  rather  starting,  in  from  the  front,  because  the  pro- 
tection of  the  other  ovens  on  the  sides  and  back  maintains  a 
slightly  higher  temperature  than  in  front  where  the  oven  is  not 
protected;  hence,  the  gases  at  their  highest  temperature  enter  the 
bottom  flues  at  the  coolest  part  of  the  oven.  By  carrying  the 
waste  gases  from  the  top  underneath  the  floor  of  the  oven,  I 
equalize,  to  a  great  extent,  the  difference  in  temperature  between 
the  top  and  bottom  of  the  oven;  not  only  this,  but  I  also  increase 
the  rapidity  of  evolution  of  the  volatile  matter  from  the  bottom, 
and  thus  in  a  given  time  remove  a  greater  volume  of  combus- 
tible matter  than  is  possible  in  the  Heminway  or  old  process. 
This  increased  combustible  matter  requires  a  large  volume  of  air 
for  its  combustion;  hence,  I  open  the  top  and  bottom  valves  con- 
nected with  the  air  supply  and  thus  add  the  required  increase  of 
air.  This  increased  amount  of  air  and  gas,  by  their  combustion, 
increases  the  amount  of  heat  produced ;  hence,  the  waste  gases  pass- 
ing under  the  bottom  of  the  oven  carry  a  corresponding  increase 


-TREATISE  ON  COKE 


183 


of  heat ;  the  greater  volume  of  air  and  gas  gives  a  greater  volume  of 
waste  gases,  all  of  which  are  conveyed  under  the  bottom  of  the 
oven,  not  only  equalizing  the  heat  in  the  mass  of  coal,  but  also 
increasing  the  rapidity  of  coking  the  coal,  thus  materially  reducing 
the  time  of  coking,  in  addition  to  obtaining  a  more  even  coke  and 
one  entirely  free  from  black  ends,  to  say  nothing  of  the  increased 
yield  which  I  obtain.  I  find  it  an  advantage  to  build  a  double 


ToB/ayr 


FIG.  18.     HEMINWAY  PROCESS  IMPROVED  BEEHIVE  COKE  OVENS 

floor  on  the  bottom  of  the  oven  because  of  the  increased  amount 
of  heat  retained  than  when  single.  One  must  also  build  the  floor 
of  the  flues  of  sufficient  thickness  to  prevent  undue  loss  of  heat 
below;  it  must  be  protected  by  a  sufficient  thickness  from  the 
effect  of  atmospheric  changes,  as  well  as  climatic  conditions,  such 
as  difference  in  temperature  between  winter  and  summer,  excessive 
rains,  etc.  The  place  and  location  of  the  ovens  will  readily  deter- 
mine what  precautions  are  necessary  to  retain  the  heat  on  the 
bottom  so  as  to  obtain  the  most  effective  work. 


184  TREATISE  ON  COKE 

To  still  further  obtain  a  more  intimate  mixture  of  air  and  gas 
in  the  oven,  I  have  added  four  openings  in  the  oven  on  a  level 
with  and  in  favor  of  the  one  lower  oval-shaped  opening.  I  thus 
throw  air  into  the  oven  at  four  separate  points  equidistant  from 
each  other,  thus  reducing  the  danger  of  unequal  and  incomplete 
combustion;  the  directions  of  these  four  openings  are  such  that 
a  line  drawn  from  the  lower  side  of  each  opening  will  strike  a 
point  just  below  the  trunnel  head  in  the  oven.  One  can  easily 
see  that  a  very  complete  mixture  of  air  and  gas  is  obtained.  If 
necessary,  two  more  openings  for  the  admission  of  air  may  be 
added  in  favor  of  the  one  upper  opening,  these  openings  to  be 
directly  opposite  each  other  and  almost  horizontal  with  the  face 
of  the  oven;  this  will  insure  a  secondary  air  supply  that  will 
thoroughly  and  evenly  mix  with  the  gases  coming  from  below  and 
result  in  complete  combustion  of  all  volatile  combustible  matter 
escaping  from  the  lower  part  or  strata  of  combustion. 

While  this  is  a  great  advance  over  the  old  method,  yet  the  rate 
of  coking  through  the  mass  is  not  as  even  as  might  be  desired!  We 
have,  in  this  case,  our  oven  hotter  at  all  times  on  top  than  on  the 
bottom  and  less  toward  the  center  than  on  the  bottom;  to  over- 
come this  I  have  arranged  to  pass  either  air  alone,  or  air  and  waste 
gas,  or  waste  gas  alone,  under  the  bottom  and  up  through  the 
mass  of  coal  in  the  oven  by  means  of  flues  or  perforated  tile,  or 
any  arrangement  that  will  allow  the  air  or  gases  'to  pass  up  through 
the  whole  bottom  of  the  oven;  for  instance,  in  my  first  trial  of  this 
I  used  the  flues  built  in  the  bottom  of  the  oven  which  I  designed 
for  drawing  off  gas,  tar,  and  liquor;  the  flues,  two  in  number,  are 
6  inches  wide  and  9  feet  from  back  to  front;  in  a  12-foot  oven 
they  are  arranged  at  equal  distances  apart  and  are  covered  with 
perforated  brick  J  inch  wide  on  top  and  ^  inch  on  the  bottom.  Air 
was  blown  in  the  bottom  through  these  flues  and,  as  might  naturally 
be  expected,  combustion  was  very  intense  over  the  flues,  so  much 
so  that  it  channeled  and  rapidly  consumed  the  volatile  matter  in 
the  coal  directly  over  the  flues.  The  coal  along  this  line  coked  very 
rapidly,  leaving  a  depression  the  shape  and  length  of  the  flue  on 
the  top  of  the  coke  due  to  the  quicker  coking  over  the  flues  and 
consequently  quicker  contraction.  Near  the  front  of  the  oven  or 
at  the  point  of  least  resistance  to  the  passage  of  air,  large  holes 
appeared,  through  which  the  air  passed  readily  to  the  top  of  the 
oven;  however,  even  with  this  crude  arrangement,  the  coke  came 
out  good;  black  ends  in  this  case  appearing  on  top  and  not  on  the 
bottom  of  the  coke.  The  time  of  coking  was  still  further  reduced, 
and  I  consider,  with  the  perforated  bottom  and  intelligent  manage- 
ment of  all  the  improvements  herein  set  forth,  we  shall  still  further 
reduce  the  number  of  so-called  non-coking  coals,  besides  reducing 
time  of  coking  of  all  coals  now  coked,  coking  a  7-ton  charge  in 
36  hours  equal  to  72-hour  coke,  improving  the  quality  and  increas- 
ing the  yield  so  that  it  runs  very  close  to  what  is  found  on  analysis. 


TREATISE  ON  COKE 


185 


The  importance  of  this  perforated  bottom  for  the  admission  of  air 
or  waste  gases,  or  a  mixture,  cannot  be  overestimated;  but  like 
all  improvements,  it  can  be  made  worse  than  useless  by  ignorant 
operation.  When  air  is  blown  into  the  bottom  of  the  oven  the 
volatile  matter  in  the  coal  is  consumed ;  at  the  point  of  combustion 
considerable  heat  is  produced  which,  passing  from  below  upwards, 
distills  the  volatile  matter  above,  and  this  increased  yield  of  volatile 
matter  increases  the  volume  of  combustible  gases;  hence,  a  greater 
volume  of  air  is  required.  This  air  is  supplied  either  through  the  air 


a-Grcu/afing  blast 


8"5uct/on  Pipe 


FIG.  19.     ARRANGEMENT  OF  FLUES  IN  IMPROVED  BEEHIVE  OVENS 

flue  on  the  top,  or,  if  the  heat  is  not  fairly  even,  a  part  or  the 
whole  of  the  combustible  gases  is  carried  to  the  bottom  of  the  oven 
where  they  come  in  contact  with  air  blown  into  the  bottom;  hence, 
combustion  of  the  volatile  matter  takes  place,  protecting  the  fixed 
carbon  on  the  bottom  of  the  oven;  and  yet  by  the  passage  of  this 
hot  burned  gas  it  distills  the  volatile  matter  remaining  in  the  mass 
of  coal  above  the  coke  on  the  bottom,  and  the  heat  passing 
rapidly  and  evenly  from  top  to  bottom  and  from  bottom  to  top, 
produces  an  even  rate  of  coking  throughout  the  mass  of  coal.  I  was 
led  to  this  improvement  through  chemical  methods  which  I  have 


186 


TREATISE  ON  COKE 


devised  for  the  removal  of  sulphur  and  which  demand  a  quick 
temperature  throughout  the  mass  of  coal  to  decompose  the  chem- 
icals used  and  bring  about  the  necessary  chemical  reactions,  without 
injury  to  the  fixed  carbon. 

The  battery  of  twenty-four  ovens  has  been  built  after  the  plans 
of  the  writer,  as  shown  in  Figs.  18  and  19.  These  ovens  are  now  in 
operation  producing  results  which  excel  even  my  anticipations. 
I  am  able  to  coke  a  5-ton  charge  of  so-called  non-coking  Illinois 
coal  in  24  hours,  and  the  coke  is  superior  in  quality.  I  am  able  to 
use  duff  which  costs  25  cents  per  ton  at  the  mine,  but  am  now 
using  pea  coal  on  account  of  the  moisture  in  washed  duff  at  this 
time  of  the  year,  about  30  per  cent.,  which  is  frozen  and  takes  too 
long  to  draw  off  in  the  oven. 

The  following  are  analyses  of  the  coal  and  the  coke: 

ANALYSES  OF  ILLINOIS  COAL 


Moisture 

Volatile  Matter 

Fixed  Carbon 

Ash 

Sulphur 

2.30 

33.58 

56.93 

7.19 

1.32 

5.71 

32.61 

52.26 

9.42 

1.93 

4.50 

31.60 

56.90 

7.00 

1.10 

4.35 

31.16 

56.79 

7.70 

1.30 

4.57 

31.53 

55.06 

8.84 

1.13 

COKE  ANALYSES 


Moisture 

Volatile  Matter 

Fixed  Carbon 

Ash 

Sulphur 

.10 

.80 

87.37 

11.73 

.90 

.09 

.64 

88.89 

10.38 

.76 

.08 

1.03 

88.71 

10.18 

.35 

.10 

1.64 

87.45 

10.81 

The  whole  of  this  work,  which  I  have  devised  and  carried  into 
practice  at  this  plant,  has  been  especially  arranged  to  treat  all 
kinds  of  coal,  and  is  working  with  the  greatest  possible  success. 
All  my  improvements  herein  described  are  the  sole  property  of 
Mr.  L.  Z.  Leiter;  my  by-product  gas  plant  is  working  with  the 
greatest  success.  It  is  the  first  time  coal  gas,  tar,  and  ammonia, 
in  addition  to  the  metallurgical  coke,  have  been  successfully  pro- 
duced in  a  beehive  form  of  oven. 

Newton-Chambers  System. — In  1895,  thirty  Newton-Chambers 
beehive  coke  ovens  were  put  in  operation  by  the  Latrobe  Coal 
and  Coke  Company,  near  Latrobe,  Pennsylvania.  For  a  time,  they 
were  operated  as  by-product  saving  ovens,  but  after  a  brief  period 
the  saving  of  by-products  was  abandoned.  The  ovens  are  now 
being  operated  in  the  usual  way  as  beehive  ovens.  They  are  of 
about  the  same  dimensions  as  the  standard  class  of  these  ovens  in 


TREATISE  ON  COKE 


187 


the  Connellsville  field,  only  the  doors  have  been  greatly  widened 
to  introduce  a  system  of  mechanical  coke  drawing,  from  the  design 
of  Mr.  Thomas  Smith,  of  the  ThornclifTe  Iron  Works,  near  Shef- 
field, England,  patented  in  1891. 

Fig.  20  shows  a  portion  of  a  bank  of  thirty  beehive  coke  ovens 
with  the  appliances  for  saving  by-products.  As  has  been  stated, 
the  effort  at  saving  by-products  has  been  discontinued.  It  is  not, 
therefore,  necessary  to  enter  into  a  description  of  these  appliances, 
as  it  was  found  undesirable  to  continue  the  effort  for  saving  the 
by-products  of  ammonia  salts,  oil,  or  tar  products,  and  gas. 

Many  efforts  have  been  made  to  supersede  the  heavy  and  hot 
manual  labor  of  drawing  coke,  by  automatic  machines,  in  the 


FIG.  20.     LATROBE  COKE  OVENS 

round  or  beehive  coke  ovens.  So  far,  little  progress  has  been 
made  in  a  practical  way  in  coke  drawing.  The  machine  for  draw- 
ing coke  at  the  Latrobe  coke  ovens,  shown  in  Fig.  20,  is  the  most 
successful  effort  thus  far  made  in  this  direction.  It  is  reported 
that  a  single  man  operating  this  extractor  can  draw  four  of  the 
large  12-foot  ovens  per  hour. 

The  Smith  coke  drawer,  Fig.  21,  consists  of  an  extractor  or  coke 
drawer  on  one  truck,  coupled  with  a  second  truck  carrying  a  small 
upright  boiler,  which  runs  on  a  track  parallel  to  the  coke  ovens. 
The  extractor  consists  of  an  engine,  operating  a  bar  a  with  a  wedge- 
shaped  plate  or  shovel  b. 

This  shovel  is  pushed  under  the  coke  in  the  oven,  the  coke  falling 
over  the  back  surface  of  the  wedge.  The  engine  is  then  reversed 


188 


TREATISE  ON  COKE 


and  the  bar  with  its  shovel  drawn  out,  bringing  the  coke  with  it. 
Along  the  front  of  the  ovens  there  is  an  apron  or  endless  con- 
veyer into  which  the  coke  falls.  The  coke  is  then  conveyed  to 
the  end  of  the  block  of  ovens  and  delivered  into  railroad  cars. 

The  Hebb  coke  drawer*  is  the  invention  of  Mr.  John  A.  Hebb, 
of  Hopwood,  Pennsylvania,  and  is  in  successful  operation  at  the 
Continental,  No.  1  plant,  of  the  H.  C.  Frick  Coke  Company.  In 
building  this  machine,  it  has  been  the  inventor's  object  to  incorpo- 
rate in  the  mechanism  the  movements  made  by  a  man  in  pulling 
coke  from  an  oven. 

In  Fig.  22  (a),  the  small  house  at  the  right  of  the  machine  con- 
tains the  electric  motor,  which,  together  with  the  coke-drawing 


FIG.  21.     SMITH  COKE  DRAWER 

mechanism,  is  mounted  on  a  truck  adapted  to  run  on  a  track 
along  the  yard  in  front  of  the  ovens. 

The  mechanical  details  of  this  coke  drawer  are  best  shown  in 
Fig.  22  (b)  and  (c),  the  former  being  a  vertical  section  on  the  line 
of  the  scraper  or  rake  beam,  transversely  of  the  track  on  which 
the  machine  runs;  and  Fig.  22  (c)  is  a  vertical  section  at  right 
angles  to  that  of  Fig.  22  (b),  and  also  through  the  center  of  parts 
mounted  on  the  revolving  table.  Referring  to  Fig.  22  (b)  and  (c), 
the  main  truck  a  supports  a  revolving  table  b  that  runs  on  rollers  c, 
the  table  being  provided  with  a  circular  track  d.  Connected  with 
the  electric  motor  is  main  shaft  e,  which  by  means  of  bevel  pinion  / 
drives  vertical  shaft  e'  by  meshing  with  bevel  wheel  /'.  Extending 
at  right  angles  with  shaft  e,  and  on  about  the  same  level,  is  shaft  g. 


*Extracted  from  Mines  and  Minerals  for  February,  1904,  p.  304. 


TREATISE  ON  COKE 


189 


From  these  main  shafts  all  of  the  various  operations  of  the  machine 
are  transmitted  through  gearing,  clutches,  and  levers. 

The  turntable  b  is  rotated  in  either  direction  by  a  hand  wheel 
connected  by  gearing  meshing  into  worm-wheel  h.  Mounted  on  the 
shaft  with  h  is  a  pinion  i  which  engages  a  circular  rack  i'  mounted 
upon  truck  a. 

The  description  of  the  scraper  or  rake  mechanism  is  readily 
apparent  upon  reference  to  the  illustrations.  The  rake  beam  /  is 
supported  on  rollers  mounted  on  standards,  at  each  side  of  central 
shaft  #',  and  which  are  secured  to  turntable  b.  At  the  upper  end 
of  shaft  e'  is  keyed  a  bevel  pinion  k  that  meshes  with  bevel  gears  kf ', 
one  on  either  side,  and  running  in  opposite  directions,  loosely  on 


FIG.  22.     HEBB  COKE  DRAWER 

shaft  /.  Beyond  gears  kf  on  each  side  is  a  friction  drum  m  keyed 
to  shaft  /.  Also  keyed  to  the  same  shaft  are  driving  pinions  n  that 
engage  racks  secured  to  each  side  of  the  rake  beam  /.  When  either 
friction  drum  m  is  brought  into  frictional  engagements  with  its 
adjacent  gear  k'  it  will  transmit  motion  to  shaft  /,  in  one  direction 
or  the  other,  according  to  which  drum  is  utilized.  The  shifting 
operation  of  the  drums  is  secured  through  lever  o,  which,  in  an  inter- 
mediate position,  holds  the  friction  drums  clear  of  the  gears.  By 
this  means,  upon  holding  one  of  the  clutches  in  contact,  the 
beam  may  be  extended  into  the  oven  to  the  desired  distance, 
and  upon  using  the  other  clutch  it  may  be  withdrawn.  Beam  / 
rests  on  rollers,  so  that  its  weight  is  not  carried  by  pinions  n. 
Above  the  beam  is  a  roller  that  provides  an  upper  bearing 
for  the  beam  and  holds  it  in  engagement  with  the  driving 


190 


TREATISE  ON  COKE 


FIG.  22.    BESB  COKE  DRAWER 


TREATISE  ON  COKE  191 

pinions.  The  forward  end  of  the  beam  is  provided  with  a 
pivotally  attached  rake  head  p,  adapted  to  fold  backwards  on 
coming  in  contact  with  the  coke  when  it  enters  the  oven,  and 
to  be  automatically  extended  to  its  upright  position  [as  shown  in 
Fig.  22  (J)]  by  the  tension  of  a  spring  at  the  back  end  of  beam. 
A  rod  connects  rake  head  p  with  the  spring. 

The  inner  (end  nearest  oven)  end  of  beam  is  raised  and  lowered 
as  follows,  shown  in  detail  at  the  left  of  Fig.  22  (c) :  Clutch  q, 
which  is  keyed  to  the  constantly  moving  shaft  e',  is  adapted  to 
engage  bevel  gears  r  and  rf,  these  latter  being  loosely  mounted  on 
shaft  e' '.  Clutch  q  is  raised  or  lowered  by  lever  5  provided  with 
a  hand  lever.  Gears  r  and  r'  engage  bevel  gear  t  keyed  to  shaft  /', 
on  which  is  worm  u,  Fig.  22  (b).  The  worm  engages  toothed 
segment  v  having  a  lever  arm.  Upward  or  downward  movement 
is  imparted  to  the  inner  end  of  the  rake  beam  through  lever  arm  in/ 
and  arms  w,  the  latter  carrying  under  and  upper  rollers  as  shown. 
Thus,  the  parts  described  permit  the  machine  to  reach  any  part 
of  the  oven  for  the  removal  of  the  coke. 

Other  devices  are  employed  for  the  purpose  of  moving  the 
entire  apparatus  along  the  track  either  for  the  purpose  of  locating 
it  to  the  right  or  left  of  the  central  position  in  front  of  an  oven  or 
for  transporting  it  from  one  oven  to  another.  The  gear  to  accom- 
plish this  result  is  connected  with  shaft  g,  which  is  constantly 
revolved  by  shaft  e  by  means  of  bevel  gears.  On  shaft  g  is  keyed 
clutch  x\  gears  y  and  y'  are  loosely  mounted  and  revolve  when 
brought  into  engagement  with  clutch  x.  Meshing  with  gears  y 
and  y  is  another  bevel,  not  shown,  through  which,  by  suitable 
connections  with  a  worm  on  axle  z,  motion  is  imparted  to  wheel  z' 
and  the  truck  moved  one  way  or  the  other  according  to  which 
bevel  clutch  x  engages.  A  lever  within  easy  reach  of  the  machine 
operator  controls  this  actuating  mechanism. 

The  removal  of  the  coke  raked  out  by  the  scraper  is  effected 
by  a  conveyer  shown  in  Fig.  22  (a). 

The  operation  of  the  machine  is  effected  by  one  man  who  stands 
on  the  turntable  b  and  faces  the  oven  door.  All  the  levers  are 
within  easy  reach,  so  that  he  can  control  any  of  the  movements 
of  the  machine  without  changing  his  position. 

Silica  Brick. — The  following  letter  from  O.  W.  Kennedy, 
formerly  general  manager  H.  C.  Frick  Coke  Company,  in  regard 
to  the  introduction  of  silica  brick,  is  self-explanatory: 

JOHN  FULTON,  ESQ.  UNIONTOWN,  PA.,  March  16,  1904. 

My  Dear  Sir: — Absence  from  home  has  delayed  reply  to  yours  of  5th. 
A  man  named  Bradley,  who  was  superintendent  of  a  silica  brick  works  at 
Layton,  Pennsylvania,  claimed  recently  to  have  been  the  first  to  suggest 
their  use  to  me  and  to  others.  He  did  so,  but  some  time  prior  to  that  a 
man  named  Drum  had  insisted  that  they  would  answer  the  purpose,  but 
no  one  paid  any  attention  to  them  until  I  took  the  matter  up  with  Bradley 
and  began  their  use  against  the  protest  of  brick  manufacturers,  oven  builders, 


192 


TREATISE  ON  COKE 


and  about  everybody  connected  with  the  business.  It  was  two  years  or 
more  after  this  beginning  before  some  brick  makers  in  this  region  could  be 
persuaded  to  abandon  the  manufacture  of  clay  brick,  and  then  only  after 
they  saw  their  trade  leaving  them. 

I  do  not  know  how  many  others  besides  Drum  and  Bradley  thought 
they  would  answer  the  purpose,  but  the  fact  is  that  I  fo.ught  the  battle  for 
silica  brick  in  coke-oven  construction  against  odds  and  opposition  that 
would  have  caused  many  a  one  to  abandon  the  project,  and  persisted  until 
their  use  became  general. 

I  would  estimate  the  life  of  a  silica  crown  at  from  12  to  15  years.  Some 
clay  crowns  have  lasted  that  long,  but  the  instances  are  rare  and  were  made 
many  years  ago.  In  the  past  10  or  12  years  they  have  ranged  from  2  months 
to  3  or  4  years.  I  think  it  would  be  entirely  safe  to  say  that  an  average 
life  would  be  less  than  3  years.  This,  of  course,  applies  to  the  Connellsville 
and  Klondike  fields.  In  some  other  coking  districts  I  believe  they  get 
along  with  the  clay  crowns  fairly  well.  Yours  truly, 

O.  W;  KENNEDY. 

Coking  Experiments  and  Results. — The  following  is  a  synopsis 
of  experiments,  with  practical  conclusions,  made  in  the  manu- 
facture of  coke  in  beehive  coke  ovens  in  the  Connellsville  region, 
Pennsylvania.  These  experiments  consisted  of  tests  at  two  coke 
works;  one  had  its  coal  treated  in  a  Heyl  &  Patterson  breaker, 
the  other  was  crushed  by  a  pair  of  rolls;  the  former  separated 
the  rough  slates,  the  latter  broke  coal  and  slate  together.  Special 
attention  was  given  to  the  effects  on  the  coke  from  coal  treated 
in  these  ways  as  well  as  from  coal  as  it  came  from  the  mine.  Con- 
clusions from  these  tests  were  arrived  at  as  to  the  management 
of  the  ovens  to  assure  the  best  results  in  the  time  used  in  coking 
and  in  the  quality  of  the  coke. 

To  determine  the  downward  rate  of  progress  in  the  coking  of 
the  coal,  measurements  were  carefully  made  showing  the  following 
rate  of  carbonization: 

TABLE   V 
RATE  OF  CARBONIZATION 


Length  of 
Time  in  Oven 
Hours 

Thickness  of 
Coal  Coked 
Inches 

Thickness  of 
Coal  Coked  in 
1  Hour 
Inch 

Length  of 
Time  in  Oven 
Hours 

Thickness  of 
Coal  Coked 
Inches 

Thickness  of 
Coal  Coked  in 
1  Hour 
Inch 

3 

3 

1 

28 

itf 

f 

12 

$i 

$  + 

48 

25 

20 

13 

1  _ 

72 

28 

1 

24 

16 

f 

It  will  be  seen  from  this  table,  as  well  as  from  the  two  illustra- 
tions of  the  downward  progress  in  coking,  Figs.  10  and  11,  pages 
159  and  161,  that  this  process  in  its  beginning  is  rather  slow, 
decreasing  until  the  twentieth  hour,  then  increasing  until  the 
twenty -fourth  hour,  moderating  at  the  twenty-eighth  hour,  after 
which  the  progress  is  slow  until  the  close  of  the  operation  at  the 


TREATISE  ON  COKE  193 

seventy-second  hour.  An  examination  of  the  coke  products  of 
48-,  72-,  and  96-hour  coke  shows  that  the  silvery  glaze  on  the 
coke  is  deposited  carbon.  Occasionally  this  carbon  is  thrown  on 
the  coke  as  soot.  These  deposits  are  mainly  found  on  the  coke  on 
the  uppermost  15  to  18  inches  of  the  coke  made. 

The  walling  up  of  the  door  of  the  oven  and  closing  the  charging 
port  give  the  following  beneficial  effects :  valuable  heat  is  retained 
in  the  oven  and  the  best  results  in  coking  are  assured. 

The  want  of  sustained  heat  in  the  oven  from  insufficient  air 
will  produce  inferior  coke  accompanied  by  the  undesirable  black 
ends  in  the  coke.  It  is  manifest  that  air  is  admitted  into  the  oven 
to  supply  the  necessary  oxygen  to  secure  the  complete  combustion 
of  the  gases  evolved  from  the  coal  in  the  coking  process.  Hence, 
the  importance  of  adjusting  the  supply  of  air  into  the  oven  to  meet 
this  necessity.  Too  much  air  will  have  the  effect  of  cooling  the 
oven.  The  largest  amount  of  gas  is  liberated  in  the  initial  opera- 
tions of  coking,  requiring  the  most  ample  supply  of  air,  say  up 
to  the  twenty-fourth  hour;  after  this  the  supply  of  air  should  be 
gradually  diminished  until  the  flaming  ceases,  when  the  oven 
should  be  entirely  closed  until  drawn. 

In  these  experimental  tests,  some  ovens  were  intentionally 
cooled  by  allowing  them  to  stand,  while  others  were  heated  by 
covering  the  charging  ports  with  dampers.  The  coke  from  the 
cooled  ovens  was  inflated  in  cellular  structure  and  had  nearly  an 
inch  of  black  ends.  The  whole  charge  showed  irregular  coking, 
with  a  poor  quality  of  coke.  The  hot  ovens  produced  a  first  quality 
of  coke,  with  good  cell  structure  and  the  absence  of  black  ends. 
Two  experiments  showed  conclusively  that  the  ovens  in  which  the 
heat  was  retained  by  walled-up  doors  and  closed  charging  ports 
produced  coke,  72  hours  after  charging,  that  was  thoroughly  car- 
bonized and  showed  little  black  ends.  From  these  tests  it  follows 
that  a  high  degree  of  heat  in  the  oven,  maintained  throughout  the 
process  of  coking,  is  essential  to  securing  the  best  results  in  hardness 
of  body  of  coke,  in  developing  its  cellular  structure,  and  in  pre- 
venting the  production  of  black  ends. 

Another  very  interesting  test  of  two  ovens  was  made.  Two 
adjacent  ovens  were  selected,  A  and  B.  Oven  A  was  closed  at 
door  and  port  hole  as  soon  as  the  charge  of  coke  was  drawn  out; 
it  was  then  allowed  to  stand  5  hours  before  recharging.  Oven  B 
was  treated  in  the  usual  way;  that  is,  it  stood  about  2  hours  before 
it  was  recharged.  No  damper  was  used  on  the  charging  port  and 
the  door  was  not  walled  up  until  after  leveling  the  charge  of  coal. 
The  charges  of  coal  were  equal  in  these  ovens,  about  145  bushels 
or  5.62  tons  each.  Oven  A  ignited  8  minutes  after  charging, 
starting  off  with  brisk  combustion,  becoming  quite  hot  10  minutes 
after  ignition.  Oven  B  ignited  32  minutes  after  charging,  starting 
off  with  feeble  combustion,  becoming  quite  hot  30  minutes  after 
ignition.  Oven  A  was  completely  burned  off  in  8  hours  less  time 


194 


TREATISE  ON  COKE 


after  charging  than  oven  B.  This  comparative  test,  which  is 
most  important  in  the  manufacture  of  coke,  was  kept  up  and  the 
reliability  of  results,  as  stated,  assured. 

It  was  demonstrated  that,  by  using  dampers  on  the  charging 
ports  and  walling  up  the  oven  doors  immediately  after  the  coke 
was  drawn,  the  heat  was  retained  and  the  best  results  in  the  quality 
of  the  coke  secured. 

With  increased  charges,  oven  A  made  its  coke  during  the 
same  time  that  oven  B,  with  less  charge,  completed  its  operation. 
The  charge  was  5.62  tons,  and  as  there  are  about  9,000  cubic  feet 

TABLE  VI 


No. 
of  Test 

Time  of  Coking  No.  1 
Oven,  Dampered  and 
Sealed  3  Hours  Before 
Charging  —  72-Hour  Coke 

Time  of  Coking  No.  2 
Oven,  Charged  Imme- 
diately After  Drawing  — 
72-Hour  Coke 

Time  of  Coking  No.  3 
Oven,  Charged  in  Usual 
Way  2  Hours  and  10  min- 
utes After  Drawing  — 
72-Hour  Coke 

Hours 

Minutes 

Hours 

Minutes 

Hours 

Minutes 

1 

53 

7 

52 

2 

59 

2 

54 

16 

57 

37 

60 

3 

58 

60 

2 

60 

4 

53 

27 

63 

34 

58 

5 

56 

20 

56 

41 

63 

30 

6 

52 

17 

60 

50 

70 

7 

55 

9 

61 

5 

59 

30 

8 

64 

40 

62 

7 

60 

9 

59 

15 

59 

34 

65 

10 

53 

30 

58 

32 

64 

11 

59 

41 

63 

51 

65 

30 

12 

56 

1 

72 

20 

59 

13 

54 

30 

59 

11 

66 

14 

54 

30 

63 

4 

60 

15 

55 

25 

63 

14 

63 

30 

16 

63 

44 

58 

30 

17 

61 

60 

18 

59 

40 

55 

19 

67 

10 

63 

20 

59 

50 

60 

Average 

56 

22 

61 

16 

61 

30 

of  gas  in  1  ton  of  this  coal  and  it  required  72  hours  in  oven  B  to 
burn  the  50,000  cubic  feet  of  gas,  it  burned  this  at  the  average  rate 
of  694.4  cubic  feet  per  hour,  a  slow  condition  of  combustion. 
Oven  A  burned  its  gas  in  64  hours,  or  at  the  average  rate  of  781.2 
cubic  feet  per  hour,  which  emphasizes  the  value  of  the  hot  oven. 

In  addition  to  the  exclusion  of  outside  air  in  retaining  or 
storing  the  heat  of  the  oven,  by  walling  up  the  doors  to  the  level- 
ing line  and  dampering  the  charging  port,  it  is  also  important 
to  charge  the  oven-  quickly  after  the  first  charge  of  coke  has  been 
removed.  This  affords  the  charge  of  coal  full  time  in  the  oven 


TREATISE  ON  COKE 


195 


to  secure  the  best  results  in  48-  and  72-hour  products  of  coke. 
Any  loss  of  heat  or  time  in  recharging  detracts  from  the  quality 
and  value  of  the  coke. 

In  harmony  with  the  foregoing  tests,  three  additional  tests 
were  made  to  determine  the  effects  of  these  methods  in  the  manu- 
facture of  coke: 

1.  The  first  set  of  ovens  was  sealed  immediately  after  the 
drawing  of  the  coke,  and  allowed  to  stand  3  hours  before  charging. 

2.  The  second  set  was  charged  immediately  after  the  coke 
was  drawn  out. 

3.  The  third  set  was  treated  in  the  usual  way,  that  is,  charged 
in  its  regular  turn,  but  not  dampered.     This  was  on  an  average 
of  2  hours  and  10  minutes  after  drawing  the  coke. 

The  charge  of  coal  in  each  oven  averaged  142.7  bushels.  The 
average  time  that  elapsed  between  the  charging  of  the  oven  and 
its  ignition  was  as  follows:  (1)  first  set,  24  minutes;  (2)  second 
set,  51  minutes;  (3)  third  set,  1  hour  and  8  minutes. 

The  time  required  in  coking  in  these  ovens  will  be  seen  in 
Tables  VI  and  VII. 

It  was  observed  that  the  ovens  in  the  first  series  maintained  a 
more  rigorous  combustion,  especially  toward  the  end  of  each  burn- 
ing, gaining  5  hours  in  time  over  the  Nos.  2  and  3  series  of  ovens. 
An  additional  test  was  made  in  the  No.  1  ovens,  by  increasing  the 
charge  of  coal  5  bushels.  The  time  of  burning  was  as  follows: 

TABLE  VII 


No. 
of  Test 

Time  of  Coking  No.  4  Oven, 
Dampered  and  Sealed  3  Hours 
Before  Charging—  72-Hour  Coke 

No. 
of  Test 

Time  of  Coking  No.  4  Oven, 
Dampered  and  Sealed  3  Hours 
Before  Charging  —  72-Hour  Coke 

Hours 

Minutes 

Hours 

Minutes 

1 
2 
3 

57 
61 
55 

30 
30 

15 

4 
5 
Average 

65 
66 
61 

15 
19 
10 

With  the  coal  charge  increased  5  bushels,  these  ovens  were 
burned  off  in  about  the  same  time  as  the  ovens  in  Nos.  2  and  3. 

Effects  in  Physical  Properties  of  Coke  Produced  by  Crushing 
the  Coal. — Investigations  were  also  made  to  ascertain  the  effects 
produced  on  the  physical  properties  of  the  coke  from  crushed  coal. 
(See  conditions  of  crushing  coal  on  page  192.)  These  tests  were 
made  at  two  plants,  one  using  coal  crushed  with  slate  separated; 
the  other  using  coal  and  its  slate  crushed  together.  We  will  desig- 
nate these  tests  A  and  B. 

Under  the  conditions  of  crushing  the  coal  at  the  coke  works  A, 
it  was  observed  that  the  lower  section  of  the  coke  in  the  oven  had 


196  TREATISE  ON  COKE 

an  infla  ea  cellular  structure.  This  led  to  the  belief  that  the  ovens 
were  overcharged  and  could  not  burn  off  as  heavy  charges  of  the 
fine  coal  as  they  could  of  the  run-of-mine.  To  test  this  the  72-hour 
charge  was  reduced  from  145  to  138  bushels,  but  this  instead  of 
improving  the  physical  structure  of  the  coke  made  it  more  spongy, 
causing  the  ovens  to  burn  off  from  10  to  12  hours  before  the  time 
of  drawing  the  coke.  The  coke  was  also  brittle  and  imperfectly 
coked.  Complaints  of  this  coke  came  from  several  parties.  The 
charges  were  restored  to  142.7  bushels,  very  decidedly  improving 
the  physical  condition  of  the  coke.  The  reduction  of  the  charges 
worked  badly  as  to  the  quality  of  the  coke  and  ihe  losing  of  heat 
in  the  oven.  These  tests  exhibited  the  difficulty  in  keeping  the 
ovens  that  are  charged  with  broken  coal  to  the  desired  high  standard 
of  heat. 

The  average  weight  of  the  coal  as  it  comes  from  the  mine  is 
78.6  pounds  per  bushel,  while  the  average  weight  of  the  broken 
coal  is  75.9  pounds  per  bushel.  It  is  therefore  evident  that  a 
bushel  of  the  run-of-mine  coal  is  3.55  per  cent,  heavier  than  a  bushel 
of  the  broken  coal,  which  means  that  1  bushel  of  run-of-mine  coal 
makes  1.0355  bushels  of  broken  coal,  after  the  coal  has  been  finely 
broken  and  the  refuse  separated.  It  was  decided  from  these  experi- 
ments, considering  the  relative  bulks  of  run-of-mine  and  breaker 
coal,  that  it  requires  a  hotter  oven  in  using  the  latter  coal  to  assure 
equally  satisfactory  results  with  the  use  of  the  run-of-mine  coal. 

Swelling  of  the  Charge. — Measurements  were  made  to  ascertain 
the  relative  amounts  of  the  swelling  of  the  charges  of  run-of-mine 
and  broken  coal.  These  measurements  were  taken  every  30  min- 
utes for  5.  hours  and  it  was  found  that  the  greatest  swelling  of  the 
charge  took  place  about  3J  hours  after  ignition.  It  was  found 
that  the  maximum  swelling  was  the  same  in  both  series,  being 
2^  inches  in  each.  It  was  considered  that  this  expansion  of  the 
charge  of  coal  in  coking  is  mainly  due  to  the  swelling  of  the  upper 
3  or.  4  inches  of  the  charge,  and  is  not  due  to  the  swelling  of  the 
whole  body  of  the  charge. 

Shrinkage  of  Charge. — Another  test  was  made  to  determine  the 
shrinkage  in  the  height  of  the  coke  due  to  watering  or  cooling  in 
the  oven.  It  was  found  that  the  shrinkage  of  a  72-hour  charge 
of  coke  is  about  -^  inch. 

Another  test  was  made  to  determine  the  relative  shrinkage  in 
cooling  the  coke  in  ovens  that  have  been  charged  with  run-of-mine 
coal  and  broken  coal.  The  former  showed  an  average  shrinkage 
of  5.36  inches,  the  latter  an  average  shrinkage  of  7  inches.  The 
height  of  the  charge  in  the  former  was  26  inches,  and  in  the  latter 
27  inches.  In  the  first  series,  run-of-mine  coal,  the  average  shrink- 
age was  20.70  per  cent,  of  the  total  height  of  the  charge;  and  in  the 
second  series,  25.95  per  cent,  of  the  total  height  of  the  charge. 


TREATISE  ON  COKE  197 

Cell  Structure. — A  test  was  made  to  determine  the  relative 
cellular  structure  in  the  coke  from  lump  coal  and  from  finely 
pulverized  coal.  The  large  lump  coal  made  a  coke  weighing 
72.50  pounds  per  cubic  foot,  and  the  finely  powdered  coal  gave  a 
coke  weighing  53.17  pounds  per  cubic  foot,  a  reduction  in  the 
weight  of  a  cubic  foot  of  coke  of  19.33  pounds.  Other  lumps  of 
coal  were  subsequently  coked,  and  the  coke  from  these  was  corre- 
spondingly heavy  and  evidently  of  closer  cellular  structure  than 
the  coke  made  from  the  broken  coal  and  pulverized  coal.  It 
follows  from  these  tests  that  the  coarser  coal  produced  a  heavier 
and  denser  coke,  the  lighter  and  more  developed  structure  being 
secured  from  the  powdered  coal. 

Relative  Weight  of  Coke. — The  crushed  coal,  the  crushing  having 
removed  some  of  the  slate  and  other  impurities,  produced  the  best 
quality  of  coke  in  its  physical  and  chemical  properties.  Fifty 
samples  of  run-of-mine  coke  gave  a  weight  of  61.61  pounds  per 
cubic  foot.  An  equal  number  of  samplings  of  broken-coal  coke 
gave  a  weight  of  60.59  pounds  per  cubic  foot,  exhibiting  a  difference 
of  91.02  pounds  in  favor  of  the  latter  Doubtless  some  of  the 
difference  in  the  weight  of  a  cubic  foot  of  each  product  is  accounted 
for  in  the  difference  of  the  cellular  structure,  but  the  main  element 
consists  in  the  purer  coke  from  the  broken  coal  with  its  impurities 
removed. 

A  test  made  to  determine  the  relative  weights  of  coke  made 
from  run-of-mine  and  broken  coal,  and  also  to  enable  a  comparison 
to  be  made  between  48-  and  72-hour  coke,  gave  the  weight  of  a 
cubic  foot  of  run-of-mine  48-hour  coke  as  58.65  pounds,  and  the 
weight  of  48-hour  coke  from  broken  coal  as  56.21  pounds  per  cubic 
foot,  or  2.44  pounds  per  cubic  foot  lighter  than  the  coke  from 
run-of-mine  coal.  The  run-of-mine  72-hour  coke  weighed  61.61 
pounds  per  cubic  foot,  and  the  48-hour  coke  weighed  58.11  pounds, 
or  3.5  pounds  lighter  per  cubic  foot. 

The  following  results  were  obtained  from  crushed  coal,  in  which 
the  coal  and  its  impurities  were  broken  together  without  any 
attempt  at  separation:  The  weight  of  72-hour  coke  from  this 
broken  coal  was  70.88  pounds  per  cubic  foot,  and  from  run-of-mine 
coal,  66.81  pounds  per  cubic  foot.  It  is  evident  that  the  broken 
coal  makes  coke  4.07  pounds  heavier  than  that  made  from  run- 
of-mine  coal.  The  crushed  coal  at  this  place  makes  a  denser  coke 
than  that  made  from  run-of-mine  coal.  It  may  be  noted  that  at 
one  of  these  works,  in  the  coal-crushing  operation,  much  of  the 
bone  and  slate  are  removed,  while  at  the  other  Tkrth  are  crushed 
together. 

A  test  was  made  to  endeavor  to  account  for  the  difference  in 
weight  of  the  coke  made  from  the  coal  in  its  two  different  treat- 
ments in  the  coke  oven.  The  bone  and  slate  separated  at  one  of 
the  works  were  collected  and  after  being  finely  broken  with  a 


198  TREATISE  ON  COKE 

hammer  were  restored  to  the  charge  of  cleaned  coal,  thoroughly 
mixed  and  charged  into  the  oven.  It  was  found  that  the  coke 
produced  with  this  mixture  afforded  substantially  the  same  weight 
of  coke  as  that  from  the  broken  coal  and  its  slate  from  the  other 
works.  Careful  test  showed  that,  in  28.70  cubic  feet  of  run-of-mine 
coal,  1.8  cubic  feet  of  refuse  was  taken,  or  6.27  per  cent.  Now, 
6.27  per  cent,  of  a  charge  of  145  bushels  of  coal  would  be 
9.09  bushels,  which  equals  the  amount  of  refuse  existing  in  a  145- 
bushel  charge.  A  cubic  foot  of  coke  made  from  this  crushed 
coal  and  slate  gave  a  weight  of  62.73  pounds.  Comparing  this 
weight  of  62.73  with  61.61,  the  weight  of  a  cubic  foot  of  coke  from 
run-of-mine  coal,  it  shows  also  that  the  weight  of  coke  from  cleaned 
coal  is  increased  1.12  pounds  per  cubic  foot  above  that  of  run-of- 
mine  coal  by  giving  the  crushed  coal  the  same  quality  as  when 
crushed  en  masse — coal  and  slate. 

At  one  of  these  works,  the  crushed  coal  and  slate  give  an 
additional  weight  of  4.07  pounds,  while  at  the  other,  under  like 
conditions,  the  increased  weight  of  the  coal  is  only  1.12  pounds  per 
cubic  foot.  The  difference  in  the  methods  of  crushing  the  coal  at 
these  two  works  does  not  fully  account  for  the  difference  in  the 
weight  of  the  coke  produced.  Evidently  the  difference  in  the 
bone  and  slate  at  these  two  mines  will  suggest  the  main  cause  of 
the  divergence  in  the  weight  of  coke  produced. 

The  evidence  of  these  tests  shows  that  the  presence  of  finely 
crushed  bone  coal  and  slate  in  the  charge  of  coal  will  produce  a 
more  restricted  cellular  structure  in  the  coke.  The  variations  of 
cellular  structure,  as  shown  by  the  previous  tests,  must  also  involve 
variations  in  the  amount  of  shrinkage,  the  uncleaned  coal  at  one 
works  giving  a  reduced  shrinkage  below  the  cleaned  coal  of  2  inches. 

Tests  of  Coking  Properties  of  Different  Portions  of  Connells- 
ville  Coal  Seam. — A  series  of  tests  was  made  to  determine  the 
quality  and  physical  properties  of  coke  made  from  the  three  natural 
divisions  of  the  Connellsville  bed  of  coal.  These  divisions  are  as 
follows:  (1)  the  coal  between  the  3-foot  binder  and  floor,  or 
bottom  of  the  seam;  (2)  the  coal  between  the  5-foot  binder  and 
the  3-foot  binder;  (3)  the  coal  between  the  5-foot  binder  and  roof. 

The  coal  for  this  test  was  secured  from  points  in  the  mine 
sufficiently  distant  to  secure  a  general  average.  The  coke  produced 
afforded  the  following  weights  per  cubic  foot:  (1)  from  bottom 
bench  of  seam,  57.86  pounds;  (2)  from  middle  bench  of  seam, 
72.50  pounds;  (3)  from  upper  bench  of  seam,  82.07  pounds. 

Coke  from  fine  coal  from  the  same  localities  in  the  mine  and 
from  the  same  benches  of  seam  weighed  as  follows :  .(1)  from  bottom 
bench  of  seam,  53.20  pounds;  (2)  from  middle  bench  of  seam, 
58.21  pounds;  (3)  from  top  bench  of  seam,  61.79  pounds. 

Comparing  the  above  results,  it  is  evident  that  the  weight  of  coke 
made  from  lump  coal  is  heavier  than  coke  made  from  fine  coal,  all 


TREATISE  ON  COKE 


199 


taken  from  the  same  localities  in  the  mine.  It  is  also  evident  that 
the  coal  from  the  top  bench  of  the  seam  affords  the  heaviest  coke,  the 
middle  bench  the  next  heaviest,  and  the  bottom  the  lightest. 

The   analyses  of  the  coke  made  from  three  benches  of  this 
large  bed  are  as  follows: 


Fixed 
Carbon 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Ash 
Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Sulphur 
Per  Cent. 

Bottom  of  seam 

91.09 

1.36 

7.55 

.010 

.558 

Middle  seam                        .  .  . 

88.78 

3.08 

8.14 

.016 

.690 

Top  seam  

81.28 

1.70 

17.02 

.028    - 

.973 

As  to  purity,  the  coke  decreases  in  quality  from  the  bottom 
to  the  top  of  the  seam. 

Axioms. — Diminutive  cellular  structure  in  the  coke  is  caused  by 
insufficient  heat  in  the  ovens,  and,  conversely,  a  high  heat  main- 
tained throughout  the  period  of  the  coking  process  is  essential  to 
the  best  cellular  structure,  hardness  of  body,  with  the  absence  of 
black  ends. 

It  is  a  decided  benefit  to  exclude  the  outside  air  as  much  as 
possible  from  the  oven  while  it  is  standing  over  between  charges, 
either  by  walling  up  the  door  or  using  a  sheet-iron  shield;  also, 
it  is  an  advantage  to  make  this  interval  at  least  2  hours,  provided 
that  the  outside  air  is  excluded. 

It  requires  a  hotter  oven  to  secure  the  best  results  in  coke  when 
using  broken  coal  than  it  does  when  using  run-of-mine  coal. 

The  coarser  the  coal,  the  heavier  is  the  coke,  and  the  finer 
the  coal,  the  lighter  is  its  coke;  the  purer  the  coal,  the  lighter 
is  the  coke.  This  is  self-evident,  as  the  impurities  of  the  coal  are 
mainly  heavier  than  the  pure  coal. 

These  experiences  are  from  the  practice  of  coking  in  the  Con- 
nellsville  seam.  Other  regions  will  require  special  studies  to  secure 
the  best  result  in  the  coke  produced. 

Where  impurities  exist  in  coal,  it  should  have  a  preparation  for 
coking  by  crushing  and  washing. 


CHAPTER  VI 


THE  RETORT  AND  BY-PRODUCT-SAVING  COKE  OVENS 

Introduction. — Two  conditions  combined  to  introduce  the  mod- 
ern retort  or  closed  coke  ovens  in  Continental  Europe:  (1)  Some 
of  the  coals  in  these  countries  inherit  a  small  percentage  of  the 
fusing  matter  so  essential  in  the  manufacture  of  coke  for  metal- 
lurgical uses;  hence,  the  retort  oven  with  its  quick  heat,  utilizing 
the  small  portion  of  this  fusing  matter  in  these  qualities  of  coal, 
supplied  this  important  requirement.  (2)  The  desire  for  supple- 
menting the  profits  of  coke  making,  by  saving  the  by-products  of 
tar,  ammoniacal  liquor,  and  gas,  from  the  gaseous  products  dis- 
charged from  the  coking  chambers  of  the  ovens  in  the  manufacture 
of  coke. 

Evidently  this  new  departure  was  suggested  to  coke  makers 
and  oven  builders  from  the  operations  in  the  manufacture  of  illumi- 
nating gas,  for  the  gas  makers,  in  the  process  of  purifying  their 
product,  required  the  elimination  of  tar  and  ammoniacal  liquor. 
It  thus  became  evident  to  coke  makers  that  the  gases  evolved  from 
the  coke  ovens  contained  similar  products  and  logically  suggested 
additional  profit  in  saving  them. 

It  is  recorded  that  the  first  coke  ovens  producing  tar  and 
ammonia  as  by-products  were  constructed  at  Sulzbach,  near 
Saarbriicken,  in  1766.  These  first  attempts  were  very  crude  and 
of  little  practical  value.  In  1781,  Sir  Archibald  Cochrane,  Count 
of  Dundonald,  obtained  a  patent  on  the  production  of  tar,  volatile 
oils,  alkalies,  acids,  pitch,  and  coke,  from  bituminous  coal.  Very 
slow  progress  was  made  in  the  saving  of  by-products ;  their  practical 
manufacture  and  sale  in  market  was  not  assured  until  about  the 
year  1883.  The  reason  for  this  slow  progress  has  been  attributed 
to  two  principal  causes:  the  low  price  of  these  products  in  market, 
on  account  of  the  supply  from  the  gasworks,  under  the  method 
in  use,  until  recently,  of  making  illuminating  gas  from  bituminous 
coal;  besides,  the  early  efforts  at  the  coke  works  were  expensive 
and  unsatisfactory,  both  in  quality  of  coke  and  value  of  by-products 
secured. 

In  1856,  Knab,  of  the  Department  Allier,  France,  built  a  group 
of  retort  coke  ovens  in  which  a  double  purpose  is  evident:  the 
saving  of  the  by-products  of  tar  and  aqua  ammonia,  and  the  manu- 
facture of  illuminating  gas.  The  gases  freed  from  tar  and  ammonia 

200 


TREATISE  ON  COKE  201 

were  returned  to  the  ovens  and  burned  in  the  flues  to  reenforce 
the  heat  for  coking.  These  ovens  are  described  as  having  narrow 
vertical  chambers,  23  feet  long,  6  feet  6|  inches  high,  and  3  feet 
3J  inches  wide.  They  were  also  provided  with  bottom  draft. 

The  principal  difficulty  in  extending  the  use  of  these  ovens,  and 
which  has  only  recently  been  corrected,  consisted  in  the  neglect  of 
proportioning  the  several  parts  of  the  oven  to  the  requirements  of 
the  quality  of  the  coals  to  be  coked.  With  the  advent  of  correct 
dimensions  in  the  retort  coke  ovens,  to  meet  the  wants  of  the  vari- 
ous qualities  of  coal,  their  increased  use  in  the  manufacture  of 
coke  and  saving  of  by-products  has  been  largely  extended. 

Jones  and  Blackwell  took  out  patents  in  1861  to  produce  tar 
and  ammonia  by  converting  coal  into  coke  in  kilns,  but  the  experi- 
ment failed. 

In  1862,  Simon  and  Carves,  of  France,  made  very  valuable 
improvements  in  the  original  plan  of  the  Knab  oven.  They  intro- 
duced side  horizontal  flues,  in  addition  to  the  bottom  flues  in  the 
Knab  oven.  The  gases  from  this  closed  oven  were  drawn  into 
condensers  and  scrubbers  by  an  exhaust  engine,  the  tar  and  ammo- 
nia separated,  and  the  remaining  gas  returned  to  supplement  the 
oven  heat.  The  construction  of  this  Knab-Carves  coke  oven,  with 
important  improvements,  in  1873,  to  assure  the  better  distribution 
of  heat,  afforded  a  model  for  subsequent  coke  ovens,  and  this 
model  was  soon  appropriated  by  Albert  Huessner,  who  is  credited 
with  the  practical  introduction  of  a  successful  oven  and  apparatus 
for  securing  by-products  from  the  coke-oven  gases.  Huessner 
built  100  ovens  in  1881,  establishing  the  by-product  industry  on  a 
sound  basis  in  Germany. 

The  quality  of  the  coke  made  in  these  ovens  was  regarded  as 
inferior,  on  account  of  the  rapid  exhaustion  of  the  gases  by  suction, 
and  it  required  many  years  with  considerable  improvements  in  the 
ovens  to  overcome  the  objection. 

The  G.  Seibel  coke  oven  was  introduced  in  France  in  1881. 
It  has  horizontal  flues  in  the  middle  of  the  walls  of  the  coking 
chambers,  with  gas  reservoir  after  the  Simon-Carves  plan,  and 
was  the  first  oven  built  without  grates  for  saving  by-products. 
At  one  plant  in  France  the  surplus  gas,  after  the  extraction  of 
by-products,  is  used  for  illuminating  purposes.  The  temperature 
obtained  in  this  oven  is  fully  equal  to  the  Otto-Hoffman  oven  with 
its  expensive  regenerators. 

The  main  element  in  the  design  of  this  oven  is  to  maintain  the 
process  of  coking  so  successfully  in  use  in  the  beehive  ovens;  that 
is,  the  carbonization  of  the  charge  of  coal  in  the  oven,  beginning  at 
the  upper  surface  and  going  downwards  to  the  bottom  of  the  oven, 
proportioning  the  heat  as  the  coking  progresses  from  top  to  floor 
of  oven.  This  secures  the  deposition  of  the  maximum  quantity 
of  carbon  from  the  evolved  hydrocarbon  gas  from  the  coal  in 
coking.  About  11  per  cent,  of  deposited  carbon  has  been  secured 


202  TREATISE  ON  COKE 

under  this  method  in  this  coke  oven,  which  not  only  glazes  the 
coke  with  nearly  pure  carbon,  but  also  adds  very  materially  to 
the  percentage  of  the  carbon  in  the  coke,  reducing,  relatively,  the 
ratio  of  impurities  to  the  carbon  in  the  coke. 

The  principles  under  which  this  oven  was  designed  by  Mr.  G. 
Seibel  are  undoubtedly  correct,  and  should  afford  excellent  results 
in  the  quality  of  coke  and  saving  of  by-products. 

About  the  time  of  the  introduction  of  the  Seibel  oven,  the 
earnest  attention  of  coke  manufacturers  was  directed  from  previous 
experience  to  the  two  prime  requirements  in  the  manufacture  of 
retort  coke:  the  production  of  good  coke,  and  the  securing  of  the 
by-products.  The  first  consisted  in  the  necessity  of  proportioning 
the  size  of  the  oven  chamber  to  meet  the  requirements  of  the 
different  qualities  of  coking  coals,  the  coals  rich  in  volatile  matters 
requiring  treatment  in  wider  ovens,  while  the  dry  coals  or  those 
low  in  volatile  matters  demanded  narrow  ovens  for  the  best  products 
in  coke. 

The  previous  inattention  to  these  prime  requirements,  especially 
in  coking  the  continental  coals  of  Germany,  Belgium,  and  France, 
caused  the  retort  cokes  to  be  regarded  with  suspicion  as  to  their 
adaptability  for  producing  coke  for  metallurgical  purposes.  It 
required  considerable  time  to  remove  this  prejudice.  The  ultimate 
credit  of  doing  so  is  attributed  to  Dr.  C.  Otto  and  Company,  of 
Dahlhausen  on  the  Ruhr,  who,  in  1881,  erected  ten  trial  ovens, 
which  laid  the  foundation  of  a  system  coming  later  into  favorable 
use,  But  it  required  the  addition  of  the  Siemens  regenerator,  in 
order  to  heat  the  air  required  for  the  complete  combustion  of  gas 
to  as  high  a  degree  as  possible,  before  a  successful  condition  was 
assured.  This  addition  was  patented  by  Gustave  Hoffman  in 
1883,  constituting  the  Otto-Hoffman  coke  oven. 

Some  criticism  has  been  made  questioning  the  value  of  the 
addition  of  the  Siemens  regenerators  to  the  Otto-Hoffman  oven, 
with  the  increased  cost  involved  by  these  appendages.  The 
arrangement  of  vertical  side  flues  is  also  regarded  as  objectionable, 
from  the  difficulty  of  distributing  the  heat  evenly,  with  the  reduced 
amount  of  it  secured. 

This  Otto-Hoffman  coke  oven  was  further  improved  by  E.  Fest- 
ner,  of  Gottesburg,  who  made  an  important  change  in  the  position 
of  the  flues  in  the  oven  side  walls,  by  using  the  horizontal  in  place 
of  the  vertical  position.  He  also  abandoned  the  Siemens  regener- 
ator, replacing  it  with  the  Ponsard  gas  furnace.  In  establishing 
these  improvements,  he  is  reported  as  having  the  cooperation  of 
Hoffman,  and  the  oven  has  been  named  the  Festner-Hoffman 
coke  oven. 

The  Semet-Solvay  oven  came  into  appreciative  notice  in  1887. 
It  is  designed  for  coking  dry  coals  or  a  mixture  of  pitchy  and  dry 
coals.  Its  side  walls  are  made  with  flued  and  jointed  tiles  in  hori- 
zontal position.  This  secures  a  maximum  heat  which  can  be 


TREATISE  ON  COKE  203 

evenly  distributed  so  as  to  avoid  the  destruction  of  firebrick  lining 
by  concentrated  heat  at  certain  localities.  The  dimensions  of  this 
oven  are  made  to  meet  the  requirements  of  the  several  qualities 
of  coking  coals  or  mixtures  of  such  coals.  It  has  two  simple  heat 
reservoirs  and  avoids  the  rather  expensive  regenerators  and  recuper- 
ators of  some  other  ovens.  It  is  usually  regarded  as  a  plain 
economical  oven,  well  adapted  to  the  saving  of  by-products. 

In  Scotland,  Mr.  Henry  Aitken,  of  Falkirk,  introduced  impor- 
tant improvements  in  the  method  of  coking  in  the  beehive  oven, 
and  subsequently  added  appliances  for  the  saving  of  by-products 
from  the  gases  of  this  oven.  The  first  improvement,  of  1874,  con- 
sisted in  the  application  of  hot  air  into  the  dome  of  the  oven,  so  as 
to  increase  the  heat  by  the  thorough  combustion  of  the  gases 
evolved  from  the  coking  coal  beneath.  This  augmented  heat  supply 
was  designed  to  save  the  burning  of  the  fixed  carbon  in  the  coking 
coal.  In  1880,  he  introduced  apparatus  for  the  saving  of  the 
by-products  in  the  beehive  ovens.  This  consists  in  the  placing  of 
a  triple  radial  perforated  conduit  in  the  bottom  of  the  oven,  con- 
nected with  an  exhaust  pipe  leading  to  condenser  and  scrubber  to 
secure  the  by-products.  These  inventions  were  quite  successful 
and  approached  at  the  time  very  nearly  to  the  best  results  in 
retort-oven  practice. 

In  England,  in  1883,  Mr.  John  Jamison  devised  methods  very 
similar  to  Aitken 's  for  saving  by-products  in  coking  in  beehive 
ovens.  He  introduced  no  change  in  the  form  of  the  ordinary 
beehive  oven,  except  to  place  channels  or  conduits  in  its  bottom, 
through  which  to  extract  the  gases  of  carbonization  by  a  slight 
suction  exhaust.  He  has  obtained  in  this  way  good  results  in  both 
coke  and  by-products. 

Simon  and  Carve's  introduced  in  England,  about  the  year  1880, 
the  improved  retort,  recuperative  coke  oven,  bearing  their  names. 
This  plan  is  a  decided  improvement  on  the  Coppee  model  in  sim- 
plicity of  design  and  efficiency  in  work,  but  the  Coppee  oven  afforded 
the  base  for  the  Otto-Hoffman  and  the  Simon-Carves.  It  has  hori- 
zontal flues  with  attached  apparatus  for  securing  the  by-products, 
and  this  plan  of  oven  has  been  quite  successful  in  producing  a 
large  percentage  of  good  coke  at  a  moderate  cost. 

In  Great  Britain,  with  its  excellent  coking  coals,  the  continental 
retort  oven  was  slow  in  finding  general  favor.  This  condition 
existed  from  the  fact  that  the  beehive  oven  produced  excellent 
coke  for  metallurgical  purposes.  The  small  wastage  of  carbon  by 
this  method  was  not  regarded  as  of  prime  importance,  as  it  was 
urged  that  the  physical  structure  of  the  coke  made  in  the  beehive 
oven  under  slight  pressure  developed  a  cell  structure  that  conferred 
superior  calorific  energy  on  this  kind  of  coke.  And  it  was  further 
submitted  that  the  smaller  product  of  the  beehive  oven,  in  blast- 
furnace use,  was  ecjual  to  the  work  of  the  larger  product  of  the 
denser  retort  coke. 


204  TREATISE  ON  COKE 

Doubtless  in  the  early  efforts  for  the  introduction  of  the  retort 
coke  ovens  the  importance  of  proportioning  their  several  parts  for 
the  coking  of  coals  of  different  qualities  was  not  so  well  understood 
as  in  more  recent  times.  Besides,  the  value  of  the  by-products 
from  the  coke  ovens  was  not  considered  in  a  manner  commensurate 
with  its  importance. 

In  the  United  States  of  America,  with  its  great  coal  fields, 
embracing  so  large  areas  of  excellent  coking  coals,  the  introduction 
of  retort  coke  ovens  has  been  slow.  This  arises  mainly  from  the 
large  cost  of  these  ovens,  especially  when  supplied  with  an  equip- 
ment for  saving  by-products.  A  secondary  hindrance  consists  in 
the  expensive  labor  cost  in  small  experimental  plants.  A  maximum 
number  of  coke  ovens  is  required  to  assure  minimum  cost  in  the 
labor  of  coke  making. 

However,  since  the  decline  of  the  production  of  tar  and  ammo- 
niacal  liquor  in  the  gasworks,  the  by-products  from  coke  works 
have  realized  a  revival  of  their  importance,  especially  the  sulphate 
of  ammonia  as  a  valuable  farm  manure,  which,  in  the  progress  of 
improved  agricultural  operations,  is  coming  largely  into  demand. 
These  have  given  retort  coke  ovens  renewed  attention  and 
importance,  and  this  will  be  further  reenforced  as  the  use  of 
coke  enlarges,  requiring  the  use  of  some  of  the  secondary  qualities 
of  coals  to  maintain  the  necessary  supply  of  this  valuable  metal- 
lurgical fuel. 

As  a  sequence  of  the  requirements  of  coke  manufacture  on  the 
continent  of  Europe,  demanding  for  successful  treatment  the  use 
of  the  closed  or  retort  coke  ovens,  the  auxiliary  apparatus  for 
saving  the  by-products  was  adjusted  to  these  types  of  ovens,  and 
some  ovens  were  designed  with  a  view  mainly  for  the  securing  of 
the  by-products.  In  Great  Britain,  with  the  satisfactory  beehive- 
coke-oven  manufacture,  the  appliances  for  saving  the  by-products 
had  their  first  application  on  this  plan  of  oven,  graduating  in  recent 
years  to  the  retort  type  of  coke  ovens.  In  the  European  countries, 
the  use  of  sulphate  of  ammonia  as  a  manure  has  received  careful 
attention,  as  this  salt  is  an  excellent  fertilizing  agent  and  is  largely 
used  in  farming  operations.  The  tar  affords  elements  that  are 
widely  used  in  many  of  the  industrial  arts. 

The  large  areas  of  superior  coals  for  making  coke  found  in  the 
United  States  and  in  Great  Britain  afford  the  best  metallurgical 
coke  in  the  beehive  oven.  This  condition,  even  with  its  expensive 
labor  and  wraste  of  fixed  carbon,  restrained  efforts  in  improve- 
ments in  the  coke  oven,  except  in  the  single  direction  of  economy 
in  the  labor  of  drawing  the  -coke  from  the  oven  by  mechanical 
appliances  in  place  of  manual  labor,  as  noticed  in  the  instance  of 
the  Welsh  coke  oven. 

But  in  Belgium  the  conditions  are  quite  different.  The  coals 
there  are  poor  in  quality  and  low  in  the  elements  that  fuse  the  coal 
in  coking.  In  this  busy  little  kingdom,  with  the  expanding  use  of 


TREATISE  ON  COKE 


205 


coke,  it  early  became  a  very  urgent  requirement  to  devise  ovens 
to  coke  their  inferior  coking  coals.  The  Belgian  coke  oven  was  the 
result  of  efforts  in  this  direction.  It  was  followed  by  a  number  of 
ovens  of  similar  construction  bearing  its  name. 

NUMBER    OF     BY-PRODUCT    COKE     OVENS    IN    USE    AND    UNDER 

CONSTRUCTION  IN  THE  UNITED  STATES  AT  THE 

CLOSE  OF  YEAR  1902,  BY  STATES 


State 

Ovens, 
December  31,  1902 

State 

Ovens, 
December  31,  1902 

Completed 

Building 

Completed 

Building 

Alabama  

240 

400 
75 
100 
30 

40 
200 

60 
574 

Ohio  
Pennsylvania.  .  .  . 
Virginia  ........ 
West  Virginia.  .  . 

Total  

50 
592 
56 
120 

60 
412 

Maryland 

Massachusetts  

Michigan  
New  Jersey  
New  York  . 

1,663 

1,346 

TABLE  EXHIBITING  THE  USE  OF  RETORT  OR  BY-PRODUCT  COKE 
OVENS  IN  THE  UNITED  STATES  FROM  1893  TO  1902,  INCLUSIVE 


Ovens 

Year 

Product 
Net  Tons 

Built 

Building 

1893 

?.2 

12,850 

1894 

12 

60 

16,500 

1895 

72 

60 

18,521 

1896 

160 

120 

83,038 

1897 

280 

240 

261,912 

1898 

520 

500 

294,445 

1899 

1,020 

65 

906,534 

1900 

1,085 

1,096 

1,075,727 

1901 

1,165 

1,533 

1,179,900 

1902 

1,663* 

l,346t 

1,403,588 

*Includes  525  Semet-Solvay,  1,067  Otto-Hoffman,  15  Schniewind,  and 
56  Newton-Chambers. 

•{•Includes  210  Semet-Solvay,  664  Otto-Hoffman,  412  Schniewind,  and 
60  Retort  Coke  Oven  Company. 

The  Belgian  oven  was  succeeded  by  a  large  variety  of  closed  or 
retort  ovens  in  Germany,  Belgium,  France,  and  recently  in  England. 
As  we  shall  consider  these  ovens  in  their  proper  order,  we  will 
endeavor  to  unfold  the  main  designs  of  their  authors  in  each  plan 
of  oven.  It  may  be  submitted  here  that  the  chief  and  imperative 
requirement  in  all  of  these  ovens  is  the  economy  of  heat  in  the 
operation  of  coking.  To  satisfy  this  prime  demand,  passages  and 


206 


TREATISE  ON  COKE 


flues  have  been  introduced  in  the  bottoms  and  walls  of  the  ovens 
to  utilize  the  heat  of  the  gases  expelled  from  the  coal  in  coking, 
returning  it  through  these  passages  and  flues  to  maintain  the 
necessary  oven  heat  in  coking. 

During  the  past  decade,  auxiliary  apparatus  has  been  attached 
to  some  of  these  ovens  and  has  been  successful  in  saving  the  chief 
by-products  of  tar  and  sulphate  of  ammonia  from  the  gases  evolved 
from  the  coal  in  coking.  After  these  by-products  have  been 
secured,  the  gases  are  returned  to  regenerators  and  used  in  the 
usual  way  in  heating  the  coke  ovens.  Any  surplus  heat  from  these 
gases  is  frequently  utilized  under  the  boilers  in  making  steam. 

Belgian  Oven. — The  Belgian  coke  oven  was  evidently  designed 
to  satisfy  three  principal  requirements: 

1.  To  meet  the  condition  of  coking  coals  of  inferior  quality, 
requiring  the  economy  of  heat  from  the  gases  by  returning  them 


(b) 


FIG.  1.     ORDINARY  BELGIAN  COKE  OVEN 

(a)J3ectipn  through  A  A;  (b)  section  through  B  B;  (c)  section  through  C  C;  (rf)  section 

of  section  through  G  G', 
(/)  plan  of  pusher  track; 


through  D  D;  (e)  end  elevation;  "(/)  plan  of  top  of  ovens;  (g)  plan  of  section  through  G  G; 
through  H  H;  (£)  plan  of  section  through  /  /; 


(h)  plan  of  section 

(K)  elevation  of  pusher  track. 


under  and  around  the  coking  chamber  of  the  oven,  through  passages 
and  flues,  and  to  retain  the  oven  heat  by  the  rapid  discharge  of  the 
coke,  cooling  it  outside  the  oven. 

2.     To   economize   the   work   of   drawing   or   discharging   the 
coke  from  the  oven  by  mechanical   appliances  in  place  of  the 


TREATISE  ON  COKE  207 

rather  slow  and  expensive  methods  of  performing  this  work  by 
manual  labor. 

3.  To  exclude  the  air  in  coking  the  coal  as  much  as  practical, 
so  as  to  save  the  waste  of  fixed  carbon  usually  made  in  ovens 
admitting  the  admixture  of  air  in  the  coking  chamber,  and  in 
affording  an  increased  percentage  of  coke  from  the  coal  charged 
into  the  oven. 

The  inferior  dry  coals  of  Continental  Europe  can  only  be  coked 
to  best  advantage  in  closed  ovens.  This  involves,  however,  the 
necessity  of  cooling  the  coke  outside  the  oven,  leaving  in  this  coke 
4  to  8  per  cent,  of  moisture,  under  ordinary  conditions.  Whether 
the  increased  product  of  coke  from  the  coal  charged  in  these 
ovens  will  compensate  for  the  augmented  moisture  in  the  coke, 
from  the  necessity  of  watering  it  outside  the  oven,  will  be  con- 
sidered hereafter  in  detail.  On  the  other  side,  by  this  rapid 
discharge  of  coke,  the  oven's  heat  is  retained  and  acts  quickly 
on  the  newly  charged  coal,  utilizing  the  small  volume  of  fusing 
matters  in  the  dry  coals. 

Fig.  1  shows  the  main  features  of  the  early  Belgian  coke  oven ; 
references  to  its  parts  are  given  on  the  drawing.  Its  general 
design  consisted  in  the  economy  of  heat  in  coking  the  inferior 
dry  coals.  The  width  and  height  of  the  oven  chamber  were 
usually  proportioned  to  meet  the  requirements  of  the  coals  to 
be  coked;  the  dryer  the  quality  of  the  coal,  the  narrower  the 
chamber  of  the  oven,  and,  conversely,  the  oven  was  made  wider 
when  coals  inheriting  more  hydrogenous  matter  were  to  be  used  in 
coke  making. 

During  the  working  of  the  bank  of  Belgian  coke  ovens,  by  the 
Blair  Iron  and  Coal  Company, -at  Hollidaysburg,  Pennsylvania, 
the  coal  used  was  from  the  Miller  (B)  seam  in  the  Bennington 
mine.  It  was  composed  as  follows: 

PER  CENT. 

Volatile  matter 22 . 38 

Fixed  carbon 68 . 50 

Ash 8 . 00 

Sulphur 1 . 12 


Total 100.00 

The  theoretic  coke  from  the  above  coal,  assuming  40  per  cent, 
of  the  sulphur  to  have  been  volatilized  in  coking,  is  77.17  per  cent. 

The  Belgian  coke  ovens,  using  this  Miller  coal,  gave  the  follow- 
ing results:  coal  charged,  6.86  gross  tons;  coke  made,  4.81  gross 
tons;  difference,  2.05  gross  tons. 

In  the  large  bank  of  Belgian  ovens,  formerly  in  use  at  the  blast 
furnaces  of  the  Cambria  Iron  Company,  at  Johnstown,  Pennsyl- 
vania, and  using  the  Miller  seam  coal,  the  yield  of  coke  was 
70.3  per  cent.,  indicating  a  loss  of  fixed  carbon  of  30.02  per  cent. 
This  coal  was  washed  in  preparing  it  for  coking  in  these  ovens. 


208  TREATISE  ON  COKE 

At  the  Bennington  bank  of  one  hundred  beehive  coke  ovens, 
using  the  Miller  coal  (B) ,  from  the  same  mine  and  of  similar  quality 
as  formerly  supplied  to  the  Belgian  ovens  at  Hollidaysburg,  the 
product  gave  an  average  yield  of  coke  of  64  per  cent.,  requiring 
1.56  tons  of  coal  to  make  1  ton  of  coke.  As  previously  shown,  this 
coal  affords  77.17  per  cent,  of  theoretic  coke.  The  beehive  ovens 
yield  64  per  cent,  of  coke,  showing  a  loss  of  fixed  carbon  of  17.06  per 
cent.  Equating  the  relative  conditions  of  moisture  in  the  Belgian 
oven,  coke  watered  outside  the  oven,  and  the  dryer  coke  of  the 
beehive  oven,  watered  inside  it,  the  increased  yield  of  coke  from 
the  Belgian  oven  over  the  beehive  oven  is  about  10  per  cent. 

The  modifications  and  additions  to  this  family  of  coke  ovens  are 
quite  numerous;  even  a  brief  description  of  their  various  forms 
would  exceed  the  limits  of  this  work.  The  main  principles  of  the 
original  Belgian  oven  have  been  retained  in  its  successors,  though 
not  always  bearing  the  family  name. 

The  ovens  selected  for  illustration  and  description  will  be  taken 
from  the  most  practical  types  for  the  manufacture  of  coke  at  this 
time,  and  also  those  specially  designed  for  supplementary  apparatus 
in  saving  the  by-products  of  dry  distillation  in  the  coking  process. 

Coppe'e  Coke  Oven. — This  oven  is  also  a  Belgian  invention  and 
was  in  use  on  the  continent  prior  to  1861.  In  1873  and  1874  it  was 
introduced  in  England,  and  has  also  been  used  in  a  few  localities 
in  the  United  States.  The  main  principles  embraced  in  the  design 
of  the  Belgian  coke  oven  are  preserved  in  the  plan  of  the  Coppee 
oven,  but  the  latter  is  much  more  complex  in  its  structure  and 
operation  than  the  former.  Fig.  2  shows  its  general  design. 

The  Coppe'e  coke  ovens  are  usually  built  in  blocks  of  twenty  to 
thirty  ovens,  and  the  plans  and  sections  referred  to  in  the  following 
description  embrace  a  block  of  twenty-two  ovens  with  draft  chimney 
and  other  appliances.  View  (a)  represents  a  longitudinal  section 
passing  through  the  middle  of  a  side  wall  of  an  oven,  on  line  C  D  of 
the  plan  (e) ;  (b)  shows  a  longitudinal  section  through  the  middle  of 
an  oven,  on  line  A  B  of  plan  {e) ;  (c)  shows  section  passing  through 
the  middle  of  an  end  side  wall,  on  line  E  F  of  plan  (e) ;  (d)  shows 
cross-section  and  elevation,  on  line  Y  Z  of  plan  (e) ;  (e)  is  a  plan 
from  the  line  G  V  of  section  (d) ;  the  courses  of  the  gases  are 
shown  by  plain  arrows,  while  the  way  of  air-courses  is  shown  by 
crossed  arrows. 

The  gas  escapes  from  the  oven  through  twenty-eight  openings  a 
situated  on  both  sides  of  the  oven,  into  the  horizontal  flue  b,  where 
it  meets  and  mingles  with  the  hot  air  brought  by  the  flue  c  and 
small  flues  d.  The  perfect  combustion  of  the  gases  takes  place  in 
the  horizontal  flues  6,  b'.  The  inflamed  gases  descend  through 
twenty-eight  vertical  flues  e  into  the  flue  /  situated  under  the  floor 
of  the  odd-numbered  oven;  in  this  flue  /  the  gases  of  the  two  side 
walls,  communicating  with  the  flue  under  the  floor,  mix  together. 


TREATISE  ON  COKE 


209 


210  TREATISE  ON  COKE 

The  gases  run  from  one  end  of  the  flue  to  the  other  in  the  flue  / 
and  then  pass  into  the  flue  /'  situated  under  the  floor  of  an  even- 
numbered  oven;  next,  the  gases  go  through  the  opening  g,  reach 
the  flue  h'  situated  under  the  regenerating  air  flues,  and  ultimately 
flow  into  the  main  flue  i.  This  main 'flue  takes  the  gases  to  the 
boilers,  or  to  the  chimney,  as  the  case  may  be. 

In  the  flues  /  situated  under  the  floor  of  the  odd-numbered  ovens, 
an  opening  g  is  provided  with  a  damper  which  regulates  the  admis- 
sion of  gases  into  the  lower  flues  h  and  h' . 

The  requisite  air  for  the  combustion  of  gases  is  taken  from  the 
outside  by  an  opening  /  situated  in  the  end  buttress  wall,  then  it 
descends  to  reach  the  regenerating  flues  k,  from  one  end  of  the 
batch  to  the  other  end  of  it.  These  air  flues  are  situated  between 
gas  flues  /,  /',  and  h,  h',  The  air  that  enters  from  the  outside  by 
the  opening  /  leaves  the  flues  k  through  the  opening  /,  having  been 
raised  to  a  temperature  of  600°  to  800°  F.  This  hot  air  ascends  the 
shaft  /  and  reaches  the  flue  c  situated  on  top  of  ovens.  Out  of  this 
flue  c  the  hot  air  is  divided  by  .the  small  flues  d,  situated  above 
each  side  wall,  into  the  flues  6,  6',  also  situated  above  the  side  walls 
and  immediately  under  the  flues  d. 

The  discharging  of  the  ovens  is  made  by  a  ram  engine,  which 
pushes  the  coke,  first  out  of  the  odd-numbered  ovens,  so  that  each 
newly  charged  oven  finds  itself  between  two  others  in  full  operation ; 
therefore,  between  two  highly  heated  ovens.  These  alternate  new 
charges  generate  gases  at  once  which  escape  on  both  sides  through 
twenty-eight  openings,  enter  the  flues  b,  b',  mingling  with  the  hot 
gases  of  the  adjoining  ovens  and  the  hot  air  supplied  through  the 
flues  d. 

From  the  foregoing  description  of  the  operations  of  this  oven, 
it  is  evident  that  in  using  very  dry  coals  the  alternate  charging 
and  discharging  of  the  ovens  is  necessary  to  the  diffusion  and  main- 
tenance of  the  oven  heat.  With  coals  richer  in  volatile  combustible 
matters,  the  ovens  could  be  drawn  in  sections,  thus  avoiding  any 
injurious  pressure  on  the  walls  of  the  ovens  by  the  swelling  of  the 
coal  in  coking.  These  ovens  are  usually  constructed  of  such  width 
and  height  as  may  be  required  in  coking  coals  inheriting  different 
volumes  of  hydrogenous  matters,  varying  in  width  from  15  inches 
to  13  inches,  with  heights  governed  by  the  same  elements  in  the 
coal  to  be  coked. 

It  is  claimed  that  the  Coppee  oven  affords  70  to  83  per  cent,  of 
coke  in  Belgium,  and  67  to  75  per  cent,  in  England.  A  bank 
of  thirty  Coppee  coke  ovens,  formerly  in  use  at  the  Conemaugh 
furnace  of  the  Cambria  Iron  Company,  constructed  with  some  modi- 
fications from  the  foregoing  plan,  especially  in  the  arrangements  of 
the  crown  flues,  gave  the  following  results  in  their  work  in  coking 
a  moderately  dry  coal  during  the  fiscal  year  1886.  The  amount  of 
coal  charged  into  the  ovens  during  the  year  was  12,630  gross  tons; 
the  coke  produced,  8,680  tons,  exhibiting  a  product  of  coke,  weighed 


212  TREATISE  ON  COKE 

after  having  been  watered  outside  the  ovens,  of  68.72  per  cent.; 

using  1 .22  tons  of  coal  to  make  1  ton  of  coke.     The  coal  used  was 

constituted  as  follows: 

PER  CENT. 

Moisture  212°  F 560 

Volatile  matter 17 . 700 

Fixed  carbon 73.  980 

Ash 7.360 

Sulphur 820 

Phosphorus 006 

It  may  be  noted  that  this  coal  is  very  low  in  its  volatile  combus- 
tible elements,  requiring  the  burning  of  some  of  the  fixed  carbon 
of  the  coal  to  sustain  the  oven  heat  in  coking.  The  leanness  of 
volatile  hydrocarbons  in  the  coals  at  the  city  of  Johnstown  is 
quite  remarkable  and  exceptional,  as  the  Appalachian  coals  east 
and  west  of  this  belt  inherit  normal  volumes  of  these  matters, 
with  their  usual  increase  westwardly. 

The  work  of  the  old  Belgian  coke  ovens  on  the  dry  coals  at 
Johnstown,  and  the  results  at  Hollidaysburg  on  the  second  quality 
of  coking  coal  from  the  Miller  (B)  seam  at  Bennington,  have  been 
considered  in  a  former  section.  The  average  result  of  a  full  year's 
work  of  a  bank  of  thirty  Coppee  coke  ovens  at  the  Conemaugh 
furnace,  supplied  with  the  dry  coal  from  the  Lemon  seam  in  the 
Johnstown  basin,  has  also  been  submitted.  The  use  of  all  these 
ovens  was  discontinued  some  years  ago,  for  reasons  that  cannot 
be  wholly  attributed  to  the  work  of  the  ovens. 

The  full  comparison  of  the  economies  of  the  open  and  closed 
ovens,  with  cost  of  construction  and  adaptability  of  plans  for 
special  coals,  will  be  considered  hereafter. 

Appolt  Coke  Oven. — A  radical  departure  from  its  predecessors, 
in  its  general  plan,  is  the  Appolt  coke  oven.  It  was  evidently 
designed  to  meet  the  general  conditions  covered  by  the  Belgian 
oven,  with  additional  elements  in  the  economy  of  the  work  of 
coking,  and  was  particularly  adapted  for  coking  dry  coals,  which 
require  a  rapid  exposure  to  a  high  temperature  in  the  initial  stage 
of  coking,  to  utilize  the  small  ratio  of  fusing  matters  in  such  coals. 

This  oven,  Fig.  3,  is  described  as  *"  consisting  essentially  of  a 
series  of  upright  rectangular  retorts,  the  longer  sides  of  the  rectangle 
being  two  or  three  times  the  length  of  the  shorter.  The  retort  is 
wider  at  the  bottom  than  at  the  top  to  facilitate  the  discharge  of  the 
coke.  These  retorts  are  grouped  in  companies  of  twelve,  eighteen,  or 
twenty-four,  as  the  requirements  may  be;  the  whole  enclosed  in  a 
large  rectangular  brick  chamber,  which  may  be  termed  the  combus- 
tion chamber,  the  retorts  being  surrounded  on  all  sides  by  air  spaces, 
these  spaces  being  in  communication,  and  the  walls  that  form  the 
sides  of  the  retorts  connected  together  by  solid  blocks  of  firebrick. 

*From  Report  of  J.  D.  Weeks,  Esq.,  to  Census  Office,  1885. 


TREATISE  ON  COKE  213 

"Between  the  firebrick  walls  of  the  combustion  chamber  and 
an  outside  brick  wall  is  a  space  filled  loosely  with  some  powdered 
substance,  as  sand  or  other  poor  conductor  of  heat,  which  allows 
a  certain  degree  of  expansion  and  contraction  of  the  firebrick  wall 
of  the  combustion  chamber  within.  This  combustion  chamber 
for  a  group  of  twelve  retorts  would  be  about  17  feet  long,  by  11  feet 
6  inches  wide,  and  13  feet  high. 

"Each  retort  is  about  4  feet  long  and  1  foot  6  inches  wide  at 
the  base,  and  3  feet  8  inches  long  and  13  inches  wide  at  the  upper 
part,  the  walls  being  about  4f  inches  thick. 

"The  ovens  are  placed  in  two  rows,  back  to  back,  the  bottoms 
being  provided  with  cast-iron  doors  strengthened  by  transverse 
bars  of  wrought  iron.  The  partition  walls  of  each  chamber,  at  a 
distance  of  from  16  inches  to  2  feet  from  the  base,  are  traversed 
by  two  rows  of  small  horizontal  openings  5£  inches  long  and  about 
3^  inches  high,  nine  on  the  wide  side  and  three  on  the  narrow  side. 
At  the  upper  part  there  are  three  similar  openings  on  the  wide 
side  only. 

"Through  these  openings  the  volatile  products  evolved  during 
the  coking  of  the  coal  pass  into  the  surrounding  open  spaces  of  the 
combustion  chamber,  where  they  are  burned  by  mixture  with 
atmospheric  air  admitted  through  holes  in  the  wide  sides  of  the 
outer  wall  of  the  oven." 

The  designs  of  these  ovens  are  very  complete,  especially  on  the 
lines  of  rapid  and  economical  work.  The  yields  of  coke  as  given 
by  the  Messrs.  Appolt  are  as  follows:  Each  retort  contains  about 
1|  tons  of  coal.  The  coking  is  usually  completed  in  24  hours. 
Belgian  coking  coal  gave  from  80  to  82  per  cent,  of  coke,  and 
English  coking  coal  72  to  73  per  cent.  No  analyses  are  given  with 
these"  statements  and  we  can  learn  little  of  the  actual  work  of  this 
oven. 

Theoretically,  this  is  a  very  perfect  oven,  yet  it  has  not  come 
into. as  general  use  as  some  of  its  competitors.  The  two  chief 
elements  in  retarding  its  more  general  use  consist:  (1)  in  its  large 
original  cost  and  in  the  expensive  cost  of  repairs;  (2)  the  great 
height  of  the  oven,  13  feet,  compelling  coking  under  much  pressure 
and  producing  in  the  middle  and  lower  sections  of  oven  coke  of 
objectionably  dense  physical  structure.  This  dense  product  of 
two-thirds  of  its  coke  must  be  injurious  to  its  character,  especially 
in  blast-furnace  use. 

It  is  probable  that  the  adverse  conclusion  of  Sir  I.  Lowthian 
Bell,  in  1871,  regarding  the  value  of  Appolt  and  other  flued- 
oven  cokes,  was  induced  by  the  dense  physical  structure  of 
these  cokes,  as  it  is  difficult  to  understand  how  their  chem- 
ical composition  could  invite  criticism,  for  the  reason  that,  in 
the  beehive  and  other  open  or  non-flued  ovens,  some  of  the 
fixed  carbon  of  the  coal  is  consumed  in  coking,  reducing  its 
volume  in  the  coke. 


214  TREATISE  ON  COKE 

Comparison  of  Oven  Types. — It  would  exceed  the  limits  of  this 
volume,  at  this  time,  to  follow  up,  in  order,  the  several  types  of 
ovens  from  the  ancient  beehive  to  the  modern  retort  oven,  but  it  is 
designed  to  submit  the  chief  successful  and  practical  types  of  these 
ovens  with  their  individual  desirable  elements. 

It  may  be  again  noted  here,  that,  in  the  progress  of  develop- 
ment of  the  by-product  industry,  three  special  root  types  of  ovens 
have  been  used:  (1)  The  beehive,  into  which  air  is  moderately 
admitted  and  its  heat  maintained  by  burning  a  portion  of  the  fixed 
carbon  of  the  coal.  Its  by-products  were  moderate  in  quantity 
as  well  as  in  value.  Aitken,  of  Scotland,  and  Jamison,  of  England, 
have  successfully  applied  to  this  type  of  coke  oven,  appliances  for 
the  saving  of  by-products  of  tar  and  ammonia.  (2)  The  Belgian, 
Coppee,  and  related  ovens  and  improvements  on  the  Knab,  which 
are  closed  or  retort  ovens  with  vertical  flues.  (3)  The  Simon- 
Carves  oven  is  a  closed  retort  oven  with  horizontal  flues  and 
recuperator. 

These  two  types  of  closed  ovens  utilize  the  oven  gases,  after 
having  been  deprived  of  by-products,  by  retaining  them  to  heat 
the  chambers  of  the  ovens,  thus  saving  the  burning  of  the  fixed 
carbon  of  the  coal  in  coking.  This  utilization  of  the  gases  evolved 
in  coking,  by  returning  them  to  supplement  the  oven  heat,  is  the 
distinctive  characteristic  of  the  family  of  retort  coke  ovens. 

The  positions  of  the  coal  in  the  chambers  of  these  three  typical 
coke  ovens  have  been  clearly  defined  by  the  three  postures  in  which 
a  common,  brick  can  be  placed.  Laying  it  horizontally  on  its 
broadest  side  shows  the  posture  of  the  charge  of  coal  in  the  beehive 
oven;  placing  the  brick  vertically  on  its  side  illustrates  the  shape 
in  which  the  coal  is  coked  in  the  Belgian  ovens;  and  by  placing  the 
brick  vertically  on  its  en<l,  the  posture  of  the  charge  of  coal  in  the 
Appolt  oven  is  accurately  represented. 

It  has  been  pointed  out  that  the  designs  of  the  coke  ovens 
following  the  original  beehive  were  chiefly  made  to  satisfy  the 
three  principal  conditions  of  the  manufacture  of  coke:  (1)  to 
coke  inferior  coking  coals;  (2)  to  economize  the  work  of  coking, 
by  mechanical  appliances;  (3)  to  secure  a  large  percentage  of  coke 
from  the  coal  charged  into  oven. 

The  relative  ultimate  economies  of  each  system  of  coking  will 
hereafter  be  considered  in  detail,  embracing  capital  invested  in 
construction  of  each  type  of  oven  plant,  the  percentage  of  coke 
obtained,  cost  of  making  it,  and  the  quality  and  value  of  the  coke 
produced. 

With  the  expansion  of  the  use  of  coke  in  metallurgical  opera- 
tions on  the  one  side,  and  the  gradual  exhaustion  of  the  areas  of 
the  best  coking  coals  on  the  other,  it  becomes  evident  that  to  meet 
the  coking  requirements  of  the  lower  qualities  of  coking  coals 
special  plans  of  coke  ovens  will  be  required  to  assure  the  best  pos- 
sible product  of  coke. 


TREATISE  ON  COKE 


215 


Modifications  of  Appolt  Coke  Ovens  at  Blanzy. — We  make  the 
subjoined  extracts  from  a  communication  to  the  Societe  de  1 'Indus- 
trie Minerale,  by  M.  Marie,  engineer  at  the  Blanzy  collieries. 
Several  types  of  ovens  have  been  employed  at  Blanzy,  where 
from  20,000  to  25,000  tons  of  coke  are  made  each  year,  but  of 
different  types  only  two  remain,  the  horizontal  Coppee  and  the 
Appolt  type. 

"A  few  modifications  have  been  introduced  in  the  Appolt  ovens 
in  order  to  utilize  the  waste  heat  for  firing  the  boilers  or  to  take 
off  the  gas  for  other  purposes.  The  Appolt  oven  generally  consists 
of  eighteen  vertical  retorts,  ar- 
ranged in  two  rows  in  a  large  heat- 
ing chamber.  The  gases  issuing 
from  the  retorts  by  narrow  hori- 
zontal apertures  at  the  bottom 
are  ignited  and  permeate  through 
the  heating  chamber,  air  entering 
by  orifices  at  different  levels. 
The  products  of  combustion 
escape  through  eight  passages  at 
the  level  of  the  lower  part  of  the 
retorts,  communicating  by  hori- 
zontal flues  with  vertical  chimneys 
at  the  four  corners  of  the  oven. 
Eight  other  and  smaller  orifices  at 
the  top  of  the  heating  chamber 
may  also  serve  to  take  off  the 
waste  flames;  but  they  are  not 
generally  employed,  as  their  use 
leads  to  a  cooling  down  of  the 
lower  part  of  the  oven.  The  out- 
let passages,  below  the  level  of 
the  gas  exits,  must  draw  along  a 
portion  of  these  gases  before  their 
complete  combustion,  and  with-  ;;'"^ 
out  their  having  contributed  to 
heating  the  oven;  so  that,  in  the 
chimneys,  and  especially  where  the  passage  is  throttled  by  dampers, 
the  temperature  is  very  high,  rendering  maintenance  costly  and 
difficult.  Moreover,  this  arrangement  gives  but  little  facility  for 
graduating  the  temperatures,  which  are  always  too  high  in  the 
middle  of  the  oven  and  too-  low  at  the  two  ends,  thus  delaying 
the  operation  of  coking  in  the  retorts  at  the  corners,  which  cannot 
be  drawn  every  24  hours. 

"In  order  to  improve  this  state  of  things,  the  direction  of 
the  gases  has  been  completely  changed.  The  gases  leave  the  retorts 
by  the  narrow  apertures  a,  a,  Fig.  4,  at  the  bottom,  and  air  for 
combustion  enters  by  the  passages  b,  c  at  different  levels  as 


FlG'4- 


MODIFICATIONS  OF  APPOLT  COKE 
OVENS  AT  BLANZY 


216  TREATISE  ON  COKE 

before;  but  the  products  of  combustion  are  entirely  evacuated 
at  the  upper  portion  of  the  heating  chamber,  and  the  gases, 
before  arriving  there,  are  obliged  to  follow  a  course  d,  e,  f  that 
forces  the  gas  and  air  to  mingle  and  enter  into  combustion,  thus 
heating  as  evenly  as  possible  all  the  parts  of  the  oven,  while 
apertures  with  dampers  are  provided  in  the  partitions  for  still 
better  regulating  the  temperature. 

"In  the  long  sides  of  the  oven  there  are  as  many  evacuation 
apertures  g  as  there  are  retorts ;  and,  besides,  at  each  end  there  are 
four  apertures  in  the  shorter  sides,  so  as  to  heat  the  corner  com- 
partments, which,  since  this  modification,  coke  as  rapidly  as  the 
others.  Each  of  these  apertures  is  fitted  with  a  damper,  which 
permits  of  regulating  at  will  the  temperature  of  coking;  and  they 
communicate  with  a  descending  chimney  i,  traversing  the  whole 
height  of  the  oven,  and  then  enter  the  horizontal  collector  /,  divided 
in  the  middle  by  a  vertical  partition  into  two  equal  parts. 

"Owing  to  this  arrangement,  the  heating  chamber  is  itself 
surrounded  by  all  these  chimneys  i,  which  heat  it  still  further  and 
protect  it  from  external  cooling,  while  the  chimneys  themselves 
are  separated  from  the  outer  masonry  by  an  air  space,  which  also 
protects  them.  From  the  collector  /,  the  gases  pass  into  another 
flue  k  by  means  of  four  apertures  fitted  with  dampers,  and,  when 
they  reach  this  flue,  the  gases  may  be  sent  at  will  under  the  boilers 
and  thence  up  their  chimneys,  or  directly,  on  the  other  side,  up 
other  chimneys,  dampers  serving  to  direct  the  gases  to  one  or 
other  end,  according  to  requirements. 

"This  double  direction  was  rendered  necessary  by  the  inter- 
mittent working  of  the  boilers,  which  are  only  in  use  by  day,  while 
it  also  permits  of  a  complete  stoppage,  so  far  as  the  boilers  are 
concerned,  for  cleaning  and  repairing  them.  The  object  of  the 
collector  /  is  to  regulate  the  draft  in  the  descending  chimneys  it 
which,  without  such  an  arrangement,  would  always  have  too  strong 
a  draft  on  the  side  where  the  gases  were  directed.  Lastly,  the  oven 
may  be  completely  closed  by  the  dampers  on  Sundays  and  holidays, 
when  the  ovens  are  not  drawn. 

"The  flues  /  and  k  and  descending  chimneys  i  are,  for  a  con- 
siderable distance,  surrounded  by  air,  which  is  raised  to  a  tolerably 
high  temperature;  and  this  heated  air  may,  if  required,  be  used 
for  the  combustion  of  the  gases  in  the  heating  chamber  by  suitably 
regulating  the  dampers.  It  was,  however,  necessary  to  discon- 
tinue the  use  of  this  hot  air  until  the  excess  of  gas  produced  by  the 
oven  was  taken  off,  as  the  temperature  which  it  produced  was  too 
high  and  might  damage  the  bricks  of  the  oven. 

"The  boilers  are  vertical  and  provided  below  with  a  series  of 
Mac-Nicol  tubes,  which  greatly  increase  their  evaporating  power. 
They  supply  steam  for  driving  the  lifts,  the  coke  breakers,  and  a 
washing  apparatus.  On  Mondays,  when  there  is  no  gas  in  the 
ovens,  it  becomes  necessary  to  heat  them  so  as  to  have  steam 


TREATISE  ON  COKE  217 

enough  to  begin  work;  and  for  this  purpose  they  are  provided 
with  grates,  so  that  they  may  be  fired  like  ordinary  boilers. 

"The  first  two  Appolt  furnaces  constructed  by  the  Blanzy  Com- 
pany in  1862  were  built,  as  usual,  of  burnt  bricks,  which  it  was 
necessary  to  cut  and  square  carefully;  but,  noticing  the  difficulty 
caused  and  length  of  time  required  by  this  work,  the  late  M.  Jules 
Chagot,  who  then  managed  the  Blanzy  Colliery,  conceived  the  idea 
of  building  the  ovens  with  unburnt  bricks,  as  practiced  in  the 
furnaces  of  glass  works.  Accordingly,  since  1866,  all  the  ovens 
have  been  constructed  in  this  manner,  except  one,  in  which  case 
there  was  no  time  to  wait  for  trie  bricks.  One  consequence  of  the 
use  of  unburnt  bricks  is  that  they  must  be  made  on  the  spot,  as 
they  cannot  be  transported  easily. 

"This  system  possesses  the  following  advantages:  (1)  facility 
for  squaring  the  bricks,  which  is  done  with  a  scraper  instead  of  by 
hammer  and  chisel,  thus  economizing  about  one-sixth  of  the  labor; 
(2)  the  faculty  of  the  unburnt  bricks  to  adhere  together,  so  as  to 
make  of  each  retort  a  monolith,  the  joints  of  which  cannot  be 
detected ;  (3)  saving  of  the  burning,  which  is  effected  when  firing 
up  the  oven,  which  must  always  be  heated  very  slowly,  whatever 
be  the  method  of  construction. 

"  In  addition  to  the  above,  the  manufacture  of  the  bricks  on  the 
spot  has  the  advantage  of  leaving  no  doubt  as  to  their  quality  and 
composition,  or  the  manner  in  which  they  may  be  expected  to 
behave  in  the  fire,  and  it  also  permits  of  varying  the  composition 
according  to  the  position  occupied  by  an  individual  brick,  of  using 
very  large  bricks  and  of  thus  diminishing  the  number  required. 
In  the  ovens  built  at  Blanzy,  the  bricks  are  at  least  25  centimeters 
(10  inches)  high;  each  course  of  a  compartment  is  built  of  six 
bricks;  four  courses  of  the  upper  portion  are  made,  each  in  a  single 
piece,  and  each  course  of  the  descending  chimneys,  also  in  a  single 
piece,  so  that  it  may  be  laid  very  rapidly.  In  cases  where  the 
bricks  are  not  required  to  adhere,  in  order  to  prevent  displacement, 
a  piece  of  wood  or  cardboard  is  introduced  into  the  joint  during 
construction  and  this  packing  piece  is  consumed  when  firing  up. 
Actual  experiment  has  shown  the  amount  of  clearance  that  must 
be  left,  which  is  greater  in  proportion  to  the  quantity  of  quartz 
entering  into  the  composition  of  the  brick. 

"Before  charging  the  oven  it  must  be  fired  up  with  great  pre- 
caution for  at  least  3  weeks ;  and  it  is  necessary  to  keep  a  watch  on 
the  expansion,  and  unscrew  the"  nuts  of  the  tie-rods  as  required. 
All  the  nuts  must  be  provided  with  lead  washers,  the  squeezing 
out  of  which  gives  warning  of  the  moment  when  they  must  be 
slacked.  Thanks  to  all  these  precautions,  it  was  found  possible  to 
construct  the  last  oven  with  twenty-two  compartments  instead  of 
eighteen,  without  the  slightest  fracture  being  perceptible  in  the 
retort.  There  is  an  advantage  in  getting  as  many  compartments 
as  possible  in  the  same  bank,  because  the  cost  of  the  two  heads  of 


218  TREATISE  ON  COKE 

the  chimneys  and  of  the  boilers  is  spread  over  a  larger  number  of 
retorts,  and  therefore  over  a  greater  production  of  coke. 

"On  noticing  what  happens  in  the  retorts  after  charging,  it  will 
be  seen  that,  during  the  greater  portion  of  the  carbonization,  the 
gas  attains  considerable  pressure  inside,  and  has  a  tendency  to 
escape,  not  only  by  the  narrow  apertures  intended  for  this  purpose 
at  the  bottom  of  the  retort,  but  also  at  the  upper  and  lower  joints 
if  they  are  not  made  well.  If,  therefore,  during  this  period,  the 
gas  be  put  in  communication  with  a  gasometer,  the  pressure  of 
which  is  regulated  very  low,  the  gasometer  will  be  filled  without 
air  entering  the  retort.  As,  in  the  present  instance,  the  gasometer  of 
the  gasworks  is  250  meters  (273  yards)  from  the  oven,  an  exhauster 
will  be  added  for  drawing  off  the  gas  from  the  retort,  while  leaving 
behind  it  sufficient  pressure  to  prevent  the  possibility  of  a  vacuum 
being  formed  in  the  retort.  It  will  be  possible,  with  practice,  to 
determine  the  time  during  which  communication  must  be  main- 
tained, and  at  the  end  of  this  period  a  valve  must  be  closed,  allowing 
the  gas  to  escape  by  the  apertures  a,  a,  Fig.  4,  for  taking  off  the 
gases.  The  gas  will  be  taken  off  by  the  pipes  /,  the  valves  h, 
and  the  general  pipes  m,  in  communication  with  the  exhauster. 
If,  later  on,  it  be  found  advisable  to  take  off  all  the  gas  for  recover- 
ing the  tar  and  the  ammoniacal  liquor,  the  apertures  a  will  be 
closed,  and  a  second  valve  n  and  pipe  o  will  be  added  for  collect- 
ing the  gas  not  intended  for  lighting.  After  their  tar  and  ammoni- 
acal liquor  are  condensed,  they  will  be  sent  into  the  flues  b,  c, 
where  they  will  burn  with  the  hot  air,  serving  to  maintain  the 
heat  of  the  ovens.  The  flues  6  and  c  are,  in  fact,  already  arranged 
for  receiving  the  gas  pipes. 

"With  Appolt  ovens,  more  labor  is  required  than  in  any  others. 
For  17  or  18  hectoliters  (mean  62  cubic  feet)  of  coal  charged, 
2  hectoliters  (7  cubic  feet)  of  coke  dust  must  be  charged  in  for 
closing  the  apertures  at  top  and  bottom,  and  also  at  least  half  that 
quantity  of  small  coke  for  protecting  the  gas  exits  a  a  and  pre- 
venting them  from  being  obstructed  by  the  coal.  When  the  coke 
is  drawn,  this  dust  and  small  coke  must  again  be  withdrawn  from 
the  batch,  which  is  a  double  work,  increasing  the  volumes  to  be 
handled  by  three-eighteenths  on  charging,  and  the  same  on 
drawing,  making  one-third  together.  Hitherto  the  drawn  coke, 
received  in  a  tram,  has  been  quenched  and  tipped  on  a  floor, 
where  the  separation,  screening,  and  loading  up  were  effected 
by  hand. 

"To  lessen  these  expenses,  the  company  put  up  a  mechanical 
screen.  Trams  of  the  drawn  and  quenched  coke  are  brought  by 
an  endless  chain  in  front  of  a  pit  into  which  the  coke  is  tipped, 
and  then  raised  by  a  Jacob's  ladder  to  the  top  of  the  shed,  whence 
it  falls  into  a  screen,  with  bars  5  centimeters  (2  inches)  apart,  which 
keeps  back  the  large  coke.  The  latter  falls  into  a  hopper,  where 
it  is  stored,  and  whence  it  may  be  charged  directly  into  wagons 


-j 

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-  1.1.  JLL.J..--1  'LI*  JJJL  I"  JJ.JJi'ljy±'J:^'-jy-J  tr  Jr  '.'''  " 

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Track              for  Co> 
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te^:rii4yi^^^ 


(14090; 


202'^ 


17303— vi 


FIG.  7.     SEIBEL  SYSTEM.     PLANT  FOR  CONDENSING  AND  COLLECTING 

a,  Expansion  regulating  tank;  b,  condenser  or  refrigerating. 


r 


T7JT?  n  rr  nlrnft?  n  TT  n  nln 


[!i.l!!lliil!lli1li!lllii  II 


tooucTS  FROM  A  DOUBLE  BATTERY  OF  TWENTY-FOUR  COKE  OVENS 
1  ;  c,  pipe;  d,  e,  scrubbers;  f,  tar  condensers;  g,  exhauster 


TREATISE  ON  COKE  219 

running  on  rails  by  a  sliding  door  at  the  bottom,  the  overplus  being 
directed  into  a  trommel  or  revolving  drum,  which  divides  it  into 
four  sizes,  from  dust  to  40  millimeters  (1-&  inches). 

"As  the  quantities  of  small  coke  produced  are  not  sufficient  for 
the  demand,  part  of  the  large  coke,  instead  of  falling  into  the  load- 
ing hopper,  will  be  sent  to  a  breaker  and  divided  by  a  similar 
trommel  into  the  same  classes  as  those  referred  to  above.  It  is 
expected  that  this  arrangement  will  permit  of  reducing  by  more 
than  half  the  labor  required.  The  dust  and  the  small  coke  required 
for  charging  into  the  retorts  with  the  coal  will  be  led  to  hoppers  at 
the  side  of  the  ovens,  whence  they  will  be  taken  by  the  charging 
trams. 

"The  coal  used  for  coking  is  of  the  long-flame  bituminous 
variety  containing:  carbon,  77.82  per  cent.;  hydrogen,  5.2; 
oxygen,  9.17;  and  nitrogen,  1.31;  with  an  average  of  6.5  per  cent, 
of  ash,  yielding  in  the  crucible  a  mean  of  63.71  per  cent,  of  coke, 
which  is  adhesive  and  rather  soft,  its  structure  showing  long 
bright  needles. 

"For  some  usages  a  harder  coke  is  made  from  a  mixture  of 
bituminous  and  anthracitous  coal.  The  latter,  obtained  from  the 
west  of  the  concession,  contains:  carbon,  82.48  per  cent.;  hydro- 
gen, 3.88;  oxygen  and  nitrogen,  6.14;  with  a  mean  content  of 
7.5  per  cent,  of  ash,  yielding  in  the  crucible  83.5  per  cent,  of  pul- 
verulent coke,  but  the  mixture  of  this  coal  with  the  bituminous 
produces  a  large  and  dense  coke,  in  which  the  above-named  needles 
are  absent." 

It  is  quite  probable  that  this  type  of  coke  oven  will  be  found 
to  be  well  adapted  for  the  successful  coking  of  the  western  coals, 
rich  in  bituminous  matter.  The  dimensions  of  the  coking  chambers 
will  require  enlargement  for  the  best  results  from  these  coals. 

Simon-Carves  Oven. — About  the  middle  of  the  18th  century, 
efforts  were  made  in  France  and  England  to  extract  the  by-products 
of  tar  and  ammonia  from  the  gases  evolved  in  coking  coal.  This 
was  stimulated  at  that  time  by  the  increasing  use  of  coke  in  the 
presence  of  a  declining  supply  of  charcoal.  These  efforts  were 
made  prior  to  the  practical  introduction  of  works  for  making 
illuminating  gas  from  coal. 

It  is  on  record  that  Bolton  and  Watts  first  erected  private 
gasworks  in  1798;  this  was  followed  by  the  construction  of  public 
gasworks  in  London  in  1813,  Paris  in  1815,  and  in  Berlin  in  1826. 
The  by-products  of  tar  and  ammonia,  at  these  early  gasworks, 
were  regarded  as  very  undesirable  resultants,  which  required 
removal  in  purifying  the  illuminating  gas,  as  at  this  time  no  useful 
place  appeared  for  them  in  the  industrial  arts. 

A  limited  application  was  provided  for  the  use  of  tar  in  Ger- 
many in  1846,  in  the  manufacture  of  roofing  felt.  In  England, 
tar  was  used  in  a  small  way,  in  1838,  for  the  preservation  of  timbers. 


220  TREATISE  ON  COKE 

This  was  followed  by  the  utilization  of  the  sulphate  of  ammonia 
as  a  fertilizer,  thus  affording  additional  revenue  to  the  gas  makers 
and  coke  manufacturers. 

A  long  interval  of  slow  progress  followed  the  early  production 
of  these  by-products  in  the  coke-making  industry.  This  arose,  in 
part,  from  the  feeling  entertained  at  this  period  that  ovens  making 
by-products  could  only  produce  an  inferior  quality  of  coke.  Doubt- 
less this  judgment  was  induced  by  the  poor  quality  of  gas-house 
coke  for  metallurgical  purposes,  and  by  the  fact  that  coke  for 
blast-furnace  use  could  only  be  made  in  beehive  or  similar  types 
of  coke  ovens,  untrammeled  by  the  cumbersome  apparatus  for 
saving  these  by-products. 

The  foundation  of  ultimate  success  in  making  a  good  quality 
of  coke  and  at  the  same  time  securing  the  by-products  was 
laid  in  France  by  Knab's  retort  coke  oven  in  1856;  but  the 
condensation  of  tar  and  ammonia  from  the  gases  from  these 
ovens  was  only  practically  successful  by  the  Haupart  and  Carves 
oven  about  the  year  1881.  This  success  imparted  to  the  saving 
of  by-products  renewed  interest  and  gave  the  coke-making 
industry  additional  value  in  France,  Germany,  and  England. 
The  most  important  improvement  in  the  Carves  oven,  from 
the  Knab,  consists  in  the  addition  of  side  flues.  The  Knab  oven 
had  only  bottom  flues. 

Mr.  H.  Simon,  in  England,  improved  the  Carves  oven  very 
materially  by  adding  recuperating  flues  in  front  of  the  ovens. 
This  recuperator  affords  ample  heat  in  the  process  of  coking  and 
overcomes  the  necessity  of  using  a  portion  of  the  fixed  carbon  of 
the  coal  for  supplemental  heat  in  coking. 

The  Simon-Carve's  retort  coke  oven  is  a  closed  oven  with  hori- 
zontal flues  and  apparatus  for  saving  by-products.  Its  introduc- 
tion was  followed  by 'a  large  number  of  retort  coke  ovens  with  and 
without  appliances  for  securing  by-products. 

The  Simon-Carves  coke  ovens,  Fig.  5,  are  constructed  to  pro- 
duce coke  suitable  for  all  industrial  purposes,  with  an  economy  of 
coal,  and  at  the  same  time  to  collect  all  the  by-products  in  the 
distillation  of  coal.  These  by-products  serve  for  the  manufacture 
of  ammonia  and  ammonia  compounds,  tar  and  all  its  derivatives, 
benzol,  carbolic  acid,  anthracene,  coloring  matter,  etc. 

In  the  Simon-Carves  oven,  the  carbonization  takes  place  in  a 
closed  retort,  and  there  is  neither  introduction  of  air  nor  combus- 
tion in  the  interior  of  the  oven.  To  convert  the  coal  into  coke, 
the  heat  is  applied  externally  through  flues  passing  under  the 
floor  and  along  the  sides  of  the  ovens.  The  heat  is  generated 
from  the  gases  obtained  in  the  ovens  from  the  coal,  but  only  after 
these  gases  have  been  deprived  of  every  particle  utilizable  as  a 
by-product.  Hot  air  is  employed  to  render  the  combustion  more 
effective,  waste  heat  from  the  ovens  being  utilized  to  heat  the  air. 
Fig.  5  illustrates  the  main  operations  of  this  oven. 


TREATISE  ON  COKE 


221 


The  coal  to  be  coked  is  conveyed  to  the  top  of  the  ovens  by 
the  coal  larry  o ;  by  opening  the  doors  of  these  larries,  the  coal  falls 
into  the  oven  through  the  ports  a.  These  openings  and  the  doors 
b  and  c  at  each  end  of  oven  are  then  tightly  closed  and  luted,  so  as 
to  prevent  the  admission  of  air.  The  valve  d  is  then  opened, 


(d) 


FIG.  5.     THE  SIMON-CARVJ&S  COKE  OVEN 


o,  o',  charging  larries;  a,  a,  charging  ports  to  ovens;  b,  c,  doors  to  each  end  of  ovens; 
*',  pipe  and  tuyeres  for  transmitting  gases;  m,  flues  under  ovens  for  gases  and  heated  air; 
j,  nozzle  to  mix  gases  with  air  in  flues  m;  g,  h,  g\,  hi,  g2,  recuperator  for  smoke  and  waste  heat 
from  flues  n\  h,  h\,  flues  to  allow  the  gaseous  products  to  escape  to  chimney;  g,  gi,  g%,  flues  for 
passage  of  air,  which  is  heated  on  its  way  by  contact  with  the  hot  walls  of  the  flues  h,  hi; 
e,  opening  on  top  of  oven  to  collect  the  gases;  d,  valve  to  regulate  the  gases;  /,  coke  wharf 
where  the  coke  is  cooled. 

putting  the  interior  of  the  ovens  in  communication  with  the 
exhauster  pipe  e.  This  conveys  the  gases  evolved  from  the  coking 
coal  to  the  condensers  and  scrubbers,  where  they  are  deprived  of 
the  by-products  and  returned  to  be  burned  with  hot  air  in  the 
oven  flues.  When  the  carbonization  is  completed,  the  doors  of 
the  ovens  are  opened  and  the  coke  pushed  on  the  platform  or 


TREATISE  ON  COKE 

wharf  /  by  a  steam  ram.  The  cooling  of  the  coke  is  done  on  this 
wharf.  The  interior  dimensions  of  this  oven  are  as  follows: 
length,  23  feet;  width,  18  to  20  inches;  height,  6  feet  6  inches. 

The  recuperator  is  an  important  and  later  element  in  this  oven ; 
it  is  described  as  follows:  Externally  to  the  brickwork  of  the 
ovens  are  provided  five  longitudinal  flues  g,  h,  glt  hlt  g2;  two  of 
these  flues,  h  and  hv  allow  the  gaseous  products  of  combustion  to 
escape  to  the  chimney,  the  other  three  flues,  g,  gv  g2,  contiguous  to 
the  former  ones,  serve  as  passages  for  the  air,  which  is  heated  on 
its  way  by  contact  with  the  walls  of  the  flues  h  and  hv  The  flues 
h  and  hl  communicate  respectively  with  the  chimney  and  the  steam 
boilers,  which  can  be  placed  at  each^end  of  the  row  of  ovens,  to 
further  utilize  the  waste  heat  of  the  products  of  combustion. 

The  charge  of  coal  for  each  oven  is  5£  net  tons.  The  coking 
requires  about  48  hours  with  the  usual  quality  of  coals.  With 
coal  affording  75  per  cent,  of  coke,  the  production  of  an  oven  is 
2.1  to  2.2  tons  of  coke  per  day,  and  about  10  per  cent,  of  ammo- 
niacal  water  and  3  per  cent,  of  tar. 

A  battery  of  fifty  ovens  at  Bearspark  Colliery,  England,  makes 
about  900  net  tons  of  coke  per  week  from  coal  constituted  as 
follows : 

PER  CENT. 

Moisture 84 

Volatile  matter 26.85 

Fixed  carbon 68 . 44 

Ash 3.10 

Sulphur 77 

Total 100.00 

The  theoretic  coke  from  the  above  coal  is  72  per  cent.  The 
charge  into  the  oven  is  5^  net  tons  of  coal,  yielding  about  4J  tons 
of  coke  in  48  hours.  Deducting  for  ashes  and  breeze,  the  product 
of  marketable  coke  is  practically  75  per  cent.  This  shows  a  small 
accretion  from  the  deposit  of  carbon  in  the  process  of  coking, 
about  4  per  cent. 

The  cost  of  labor  in  coking  and  collecting  by-products  is  esti- 
mated at  48  cents  per  net  ton  of  coke  made  in  a  battery  of  fifty 
ovens,  producing  together  105  tons  of  coke  per  24  hours.  The 
annual  product  of  fifty  ovens  of  marketable  coke  would  be  about 
34,000  net  tons.  The  value  of  the  by-products  of  tar  and  ammo- 
nia is  estimated  at  68  cents  per  net  ton  of  coke  made. 

The  cost  of  a  plant  of  fifty  Simon-Carves  ovens  with  appliances 
for  saving  the  by-products  would  be  about  as  follows  in  the 
United  States,  depending  somewhat  on  locality: 

Fifty  ovens  at  $1,300  each $  65,000.00 

By-products  appliances,  tracks,  houses,  elevators, 

etc 50,000.00 


Total/ $115,000.00 


TREATISE  ON  COKE  223 

This  estimate  does  not  embrace  a  coal-washing  plant.  If  such 
is  required,  an  additional  sum  must  be  added  to  the  above,  depend- 
ing on  the  character  of  the  coal  and  the  impurities  to  be  removed. 

With  coals  inheriting  26  per  cent,  of  volatile  matter  the  saving 
of  by-products  becomes  more  assured,  but  with  the  large  expense 
of  the  apparatus  for  saving  by-products  in  the  original  cost  of  the 
coking  plant,  and  in  its  continuous  and  expensive  operation  and 
maintenance,  it  becomes  a  matter  demanding  careful  investigation 
whether  at  this  time  it  is  an  auxiliary  that  will  surely  afford  to 
the  coke  manufacturer  an  income  that  will  compensate  for  invest- 
ments in  this  addition  to  the  plant,  and  afford  a  return  to  cover 
the  additional  labor  and  repairs  of  apparatus.  A  thorough  test  of 
the  coal,  for  its  value  in  affording  by-products,  should  be  made 
as  a  prime  element  in  the  investigation  of  this  matter. 

These  Simon-Carves  ovens  can  be  used  in  the  manufacture  of 
coke,  with  or  without  appliances  for  the  saving  of  the  by-products 
of  tar  and  ammonia.  Their  system  of  horizontal  flues  is  com- 
mended for  efficiency  and  economy  of  repairs. 

G.  Seibel's  Retort  Coke  Oven.— By-Product  Oven.— The  Seibel 
retort  coke  oven  was  patented  by  its  inventor,  Georges  Seibel,  in 
France,  in  1881,  in  England,  in  1882,  and  in  the  United  States  of 
America,  in  1883.  Two  main  principles  appear  to  have  been  kept 
in  view  by  Mr.  Seibel  in  the  planning  of  this  oven.  (1)  To  preserve 
the  mode  of  carbonization  that  secures  a  maximum  deposit  of 
carbon  from  the  hydrocarbon  gases  in  their  ascent  through  the 
upper  incandescent  coking  portion  of  the  charge.  (2)  To  arrange 
tuyeres  and  horizontal  flues  for  the  utmost  economy  in  maintain- 
ing oven  heat  by  combustion  of  the  returned  gases,  deprived  of 
the  by-products,  without  the  use  of  grates  or  complicated  regen- 
erators. The  details  of  this  oven  are  all  in  harmony  with  these 
principles,  exhibiting  practical  skill  in  the  design  of  the  retort  coke 
oven  and  its  by-product-saving  appliances. 

Through  the  courtesy  of  Mr.  W.  M.  Stein,  of  Primos,  Pennsyl- 
vania, I  am  enabled  to  submit  the  considerations  that  guided  Mr. 
Seibel,  the  inventor,  in  designing  this  oven,  from  his  own  notes, 
with  a  description  of  the  oven  and  its  mode  of  operation. 

"Until  recent  years,  the  method  of  coking  in  hermetically 
closed  ovens,  permitting  the  saving  of  tar  and  ammonia,  was  not 
considered  a  good  one  by  the  best  engineers.  It  was  generally 
believed  that,  at  best,  only  coke  of  inferior  quality  could  be 
obtained,  hardly  comparable  with  that  of  gasworks. 

"For  a  long  time,  the  coke  ovens  of  the  works  of  Marais,  near 
St.  Etienne,  Loire,  modified  according  to  the  Knab  system,  failed 
to  find  imitation.  Today  this  method  of  carbonization  with 
saving  of  by-products  is  more  appreciated,  its  advantages  recog- 
nized, and  the  prejudice  entertained  against  the  process  is  given 
up,  especially  in  Europe. 


224  TREATISE  ON  COKE 

"Experience  has  demonstrated  that  the  coke  thus  obtained  is 
not  inferior  in  quality  to  that  obtained  from  the  same  coal  in  ovens 
of  the  other  systems.  Germany  has  adopted  ovens  heated  with 
regenerated  gas  for  saving  of  tar  and  manufacturing  sulphate  of 
ammonia. 

"The  engineers  today  study  and  apply  the  different  systems. 
Belgium  has  ovens  heated  with  gas  and  arranged  to  gather  tar 
and  aqua  ammonia,  producing  at  the  same  time  perfect  coke, 
suitable  for  all  metallurgical  purposes. 

"In  France,  on  the  contrary,  this  question  seems  to  have 
remained  indifferent  to  the  interested  parties.  One  large  iron 
company  only,  the  company  of  Terrenoir  Savoutte  and  Besseges, 
had  adopted  the  ovens  of  the  system  Carves  and  Company,  in 
1867.  In  three  intervals,  in  1867,  1873,  and  1875,  this  company 
has  built  at  Besseges,  eighty-five  ovens  of  this  type,  being  per- 
fectly satisfied  with  the  results.  A  group  of  these  ovens  is  also  in 
operation  for  the  past  few  years  at  Terrenoir. 

"Such  is  the  condition  of  carbonization  with  saving  of  by- 
products in  the  principal  coal  centers  of  Europe. 

"It  may  be  said,  however,  that,  though  this  question  met  with 
little  interest  in  France,  it  is  beyond  dispute  that  the  improvement 
originated  in  this  country.  In  this  direction,  the  Company  of  the 
Mines  of  Campagnac  located  at  Crausac,  Aveyron,  has  been  quite  suc- 
cessful, effecting  a  remarkable  improvement  in  the  coking  industry. 
In  1878  and  1879,  this  company  built  a  first  battery  of  nine  ovens, 
modifying  the  previously  adopted  method  of  carbonization.  The 
result  obtained  surpassed  all  expectation.  In  1882,  the  company 
added  ten  ovens  to  its  first  battery,  which  have  given  the  same 
satisfaction  as  the  first.  The  mere  enumeration  of  these  results 
will  be  amply  sufficient  to  emphasize  the  progress  accomplished. 

"The  coal  of  the  Company  of  the  Mines  of  Campagnac  gives 
theoretically  an  average  yield  of  64  per  cent,  of  coke,  ashes  inclu- 
ded, and  36  per  cent,  of  volatile  matter.  The  actual  yield  of  these 
ovens  (Seibel)  proved  to  be  75  per  cent.  The  results  obtained 
during  the  whole  year  1883  were,  as  above  noted,  75  per  cent., 
that  is,  11  per  cent,  in  excess  of  the  theoretical  yield. 

"The  production  of  tar  was  54  pounds  per  each  gross  ton  of 
coal  charged.  From  these  results  the  following  figures  exhibit 
the  working  of  these  ovens  during  the  year  1883:  coal  charged 
into  ovens,  14,675  gross  tons;  production  of  coke,  11,006^  gross 
tons;  saving  of  tar,  360f  gross  tons. 

"The  Company  of  Campagnac  commenced  to  save  the  aqua 
ammonia  and  manufacture  sulphate  of  ammonia  only  after  the 
beginning  of  the  year  1883.  The  yield  of  sulphate  of  ammonia  is 
11  pounds  for  each  gross  ton  of  coal  charged.  The  company  then 
increased  the  surface  of  the  -condensing  apparatus  of  the  gases. 
The  tar  production  showed  the  effect  immediately,  increasing  to 
66  pounds  for  each  gross  ton  of  coal  charged. 


TREATISE  ON  COKE  225 

"It  follows  from  these  figures  that  a  coke  oven  of  this  system, 
using  this  or  a  similar  quality  of  coal,  will  produce  yearly  as  fol- 
lows: 648.81  net  tons  of  coke,  25.99  net  tons  of  tar,  and  4.325 
net  tons  of  sulphate  of  ammonia. 

"These  results  require  no  comment,  I  shall  therefore  not  dwell 
upon  them,  but  complete  the  information  by  adding  that  the  coke 
made  from  this  coal  is  superior  in  quality  to  that  obtained  from 
similar  coal  in  either  the  Appolt  or  Coppee  ovens. 

"We  have  during  several  months  made  coke  regularly  with 
our  coal  in  those  two  types  of  ovens  and  ours,  and  could  therefore 
determine  the  difference  in  the  products,  which  was  very  easily 
perceptible. 

' '  The  coke  obtained  from  our  ovens  is  harder  and  denser  than 
that  obtained  in  the  ovens  named  above.  This  improvement  is  the 
consequence  of  the  increase  of  yield,  which  surpasses  the  theoret- 
ical yield  by  11  per  cent.  This  increase  is  obtained  at  the  expense 
of  the  carbon  of  the  hydrocarbons  of  the  gases,  which,  dissociating, 
deposit  part  of  their  carbon  in  the  pores  of  the  coke.  In  short, 
there  is,  during  the  period  of  distillation,  a  dissociation  of  the  gases, 
whereby  a  part  of  their  carbon,  being  now  in  elementary  form, 
unites  itself  with  the  coke  or  fixed  carbon,  enriching  it  and  increas- 
ing its  quantity  and  quality. 

"Before  describing  the  ovens,  I  will  sum  up  the  reasons  which 
have  been  guiding  me  in  their  construction. 

' '  It  has  been  proved  long  ago  that  the  hydrocarbon  gases  pro- 
duced by  the  distillation  of  the  coal  give  up,  under  certain  favor- 
able conditions,  a  larger  or  smaller  proportion  of  their  combined 
carbon.  The  formation  of  graphite  in  the  retorts  of  gasworks  is 
due  to  this  cause.  On  the  other  hand,  if  one  compares  carefully 
the  coke  produced  in  a  beehive  oven  with  the  coke  from  the  same 
coal  produced  in  ovens  of  the  other  types,  it  will  be  recognized  that 
the  coke  from  the  beehive  ovens  is  denser,  harder,  and  in  thicker 
pieces  than  that  produced  by  ovens  of  other  systems.  The  differ- 
ence is  especially  marked  in  coke  from  coals  rich  in  volatile  matter 
like  those  of  the  basin  Decazeville  and  Aubin.  This  difference  in 
quality  was  formerly  so  well  known  in  the  basin  of  Decazeville 
that  the  foundry  owners  would  take  only  beehive  coke  for  smelting 
in  cupolas,  excluding  coke  from  the  ovens  Semet,  Appolt,  and 
Coppee,  which  was  formerly  used  simultaneously  with  beehive  coke 
in  these  works.  The  difference  in  quality  can  only  be  due  to  the 
manner  of  carbonization.  In  the  beehive  ovens  formerly  used, 
the  process  of  coking  commences  at  the  top  and  then  goes  down- 
wards. Now,  if  a  charge  of  coal  is  put  in  a  heated  beehive  oven, 
all  parts  of  the  oven  with  which  the  coal  comes  in  contact,  walls 
and  bottom,  cool  immediately,  the  dome  only  retaining  its  heat. 
The  latter  radiates  heat  over  the  charge  and  starts  the  distillation 
there.  This  distillation  continues  downwards  in  the  mass  of  coal, 
and  the  gases  produced  in  the  lower  portions  are  forced  to  traverse 


226  TREATISE  ON  COKE 

a  porous  mass  during  the  formation  of  coke,  in  order  to  escape 
through  the  only  opening  in  the  roof.  The  hydrocarbon  gases 
traversing  in  the  early  stage  of  the  coking  process  through  a 
spongy  mass  are  consequently  surrounded  by  conditions  very  favor- 
able to  their  dissociation,  and  give  up  to  the  upper  regions  of 
the  charge  a  certain  proportion  of  their  carbon.  This  fact  can  be 
proved  by  a  careful  examination  of  a  coke  needle.  These  needles 
are  formed  vertically  in  the  beehive  ovens ;  at  the  lower  part  of  the 
needle,  where  it  touches  the  bottom  of  the  oven,  the  grain  of  the 
coke  is  porous,  puffed  up,  coarse;  while  it  gradually  becomes  finer 
and  denser,  approaching  the  top  of  the  needle.  The  only  possible 
explanation  of  this  difference  in  the  condition  of  the  same  needle 
is  the  one  given  above;  it  gives,  therefore,  a  valuable  hint  as 
to  the  dimensions  and  particular  arrangement  that  must  be 
observed  in  designing  the  oven.  In  spite  of  the  quality  of  the 
coke  produced  in  the  beehive  ovens  in  the  basin  of  Decazeville 
and  Aubin,  they  have  been  abandoned.  They  yielded  too  small 
a  quantity  of  coke. 

"Assisted  by  the  observations  just  related  and  information 
gained  in  the  position  of  managing  engineer  at  the  mines  of  Decaze- 
ville, I  had,  when  called  upon  to  construct  coke  ovens  for  the  Com- 
pany of  the  Mines  of  Campagnac,  already  studied  up  a  type  of 
oven  reproducing  the  method  of  carbonization  in  use  in  the  beehive 
oven,  that  is,  where  carbonization  commences  at  the  top  and 
extends  downwards,  but  avoiding  the  losses  that  are  incurred  by 
combustion  of  the  fixed  carbon. 

' '  The  retort  coke  ovens  of  the  Company  of  the  Mines  of  Cam- 
pagnac carbonize  from  the  top  downwards  and  are  hermetically 
sealed. 

"The  following  very  simple  arrangement  was  adopted.  As 
mentioned  above,  the  Company  of  the  Mines  of  Campagnac  possesses 
a  group  of  nineteen  ovens  constructed  in  two  batteries.  The  first 
experimental  battery  of  nine  ovens  and,  in  addition  to  these,  ten 
others  have  been  built,  the  south  end  of  the  first  battery  being  the 
north  end  of  the  second.  Each  retort  oven  is  a  long,  narrow, 
arched  chamber,  19  feet  8J  inches  long,  6  feet  6}  inches  high,  and 
27^  inches  wide  between  the  side  walls. 

"The  dimensions  of  a  more  modern  oven  are  given  in  Fig.  6. 
The  walls  separating  each  oven  from  its  neighboring  one  are  15} 
inches  thick  and  are  built  of  first-class  firebrick.  The  walls  between 
the  ovens  contain  three  horizontal  flues,  connected  with  each  other 
at  their  ends,  so  as  to  form  a  continuous  flue,  as  indicated  by  a,  b,  c, 
which  is  continued  in  d,  under  the  sole  of  the  oven,  and  finally 
leads  through  the  flue  e  into  the  main  gas  flue  f.  The  latter  takes 
the  gases  to  the  chimneys,  built  at  the  ends  of  the  battery  of  ovens. 
The  upper  flue  a  has  an  opening  at  g,  going  through  the  wall  to 
the  outside  of  the  oven  in  which  the  gas  burner  is  placed  and 
which  will  be  described  further  on. 


TREATISE  ON  COKE 


227 


228  TREATISE  ON  COKE 

"In  the  middle  of  the  retort  of  each  oven,  there  is  in  the  arch 
an  opening  h  that  allows  the  gases  of  distillation  to  escape.  To  the 
right  and  left  are  placed  symmetrically  the  two  other  openings 
i  and  /  for  charging  the  coal. 

"The  ovens  are  closed  at  their  ends  by  cast-iron  doors.  Two 
swinging  doors  are  placed  over  these.  The  doors,  as  well  as  the 
charging  ports,  are  hermetically  sealed  by  a  clay  point.  Above  the 
opening  h,  which  allows  the  gases  of  distillation  to  escape,  a  ver- 
tical cast-iron  pipe  k  is  placed,  which,  by  a  branch  k,  connects  with 
a  small  barrel  /,  the  opening  of  which  can  be  closed  by  a  valve  m. 
It  is  only  necessary  to  lift  the  latter  by  its  handle  to  effect  the 
stoppage.  The  gases  of  the  distillation  escape  by  means  of  the 
pipes  k  and  k  into  the  hydraulic  main,  common  to  each  battery. 

"The  hydraulic  main  is  connected  with  a  collecting  pipe  n,  by 
a  vertical  pipe  o,  which  is  also  provided  with  a  valve.  Each  battery 
has  its  hydraulic  main  connected  with  the  collecting  pipe  n,  which 
leads  the  gases  of  all  the  ovens  to  the  condensing  apparatus.  An 
exhauster  worked  by  steam,  which  absorbs  these  gases,  forces  them 
to  traverse  the  various  apparatuses  with  gradually  decreasing  pres- 
sure. The  gas  gives  up  its  tar  and  ammoniacal  water,  and  is  then 
returned  to  heat  the  ovens. 

"The  purified  gas  is  driven  back  by  the  exhauster  to  the  pipe  p 
which  extends  along  the  top  of  the  ovens.  From  this  pipe,  the 
gases  are  distributed  equally  to  the  tuyeres  by  secondary  pipes  q, 
which  take  to  the  burners  the  quantity  of  gas  necessary  for  each. 
The  pipes  q  are  supplied  with  valves  that  regulate  or  stop  the  flow 
of  gas  to  the  burners.  These  burners  consist  of  two  tubes,  one 
within  the  other,  and  closed  at  the  outer  end  by  a  flange.  The 
inner  one  is  a  little  smaller  than  the  outer  one,  so  as  to  have  a 
circular  space  of  .039  inch.  Thus  joined  with  the  flanges  put 
together,  and  the  outer  tube  connected  with  the  feeding  pipe  by  a 
special  small  tube,  it  will  be  seen  that  the  arriving  gas  flows  in 
the  upper  part  of  the  circular  aperture  between  the  tubes  in  the 
form  of  an  elongated  crown.  The  air  necessary  for  this  crown  of 
gas  reaches  the  circular  aperture  by  means  of  openings  in  the 
inner  tube.  The  supply  of  air  can  be  regulated  by  shutting  these 
openings  more  or  less. 

"These  are  the  general  arrangements  of  the  oven;  it  will  now 
be  easy  to  understand  its  operation. 

"When  an  oven  is  charged  and  cut  off  from  the  battery  by 
closing  the  valve  m  in  the  small  barrel  /,  it  is  then  recharged  with 
coal  through  the  openings  i,  /,  by  means  of  the  larries  r,  r.  The 
charge  of  coal  is  piled  up  as  high  as  possible  in  the  oven,  nearly  to 
the  spring  of  the  arch,  and  is  then  leveled  from  both  sides  through 
the  upper  opening  of  the  doors,  which  remain  open  while  the  coal 
is  charged.  This  being  done,  the  charging  ports  i,  j  are  closed 
by  lids  and  the  upper  openings  of  the  doors  shut,  both  being  her- 
metically sealed  with  clay. 


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P  IODUCTS  FROM  A  DOUBLE  BATTERY  OF  TWENTY-FOUR  COKE  OVENS 
;  c,  pipe;  cf,  ^,  scrubbers;  /,  tar  condensers;  g,  exhauster 


TREATISE  ON  COKE  229 

"At  the  same  time,  the  valve  m  of  the  barrel  /  is  opened  and 
the  communication  of  the  oven  with  the  hydraulic  main  restored. 
The  carbonization  now  proceeds  regularly,  the  gases  of  distillation 
escaping  under  a  small  pressure  through  the  opening  h,  and,  by. 
means  of  the  pipe  k,  k,  to  the  hydraulic  main,  from  whence  they 
go  to  the  condensing  apparatus. 

"The  coal  charged  being  wet,  the  walls  and  floor  of  the  oven  in 
contact  with  it  are  considerably  cooled.  The  arch  is  the  only  part 
of  the  oven  remaining  hot. 

"On  the  other  hand,  the  two  burners  have  continued  heating 
the  wall  flues  a,  which,  in  their  function  as  combustion  chambers 
of  the  gases,  have  a  higher  temperature  than  the  flues  b,  c.  It  is, 
therefore,  easily  understood  that  the  upper  part  of  the  charge  will 
receive  from  the  flues  a,  as  well  as  from  the  hot  arches  by  radiation, 
the  greatest  amount  of  heat. 

"The  distillation  begins  therefore  very  actively  at  the  top  of 
the  charge  and  progresses  downwards.  It  will  be  seen  from  this 
that  the  carbonization  begins  at  the  top  and  goes  downwards, 
exactly  as  in  the  beehive  ovens.  The  gases  generated  in  the  lower 
part  of  the  charge  must,  in  order  to  escape  through  the  only 
opening  h  in  the  oven,  traverse  the  upper  regions,  which  are  ready 
settled  and  have  been  brought  to  a  high  temperature.  This  shifting 
of  the  gases  causes  them  to  give  up  part  of  their  combined  carbon, 
which  settles  in  the  pores  of  the  coke  already  formed  and  in  the 
fissures  between  the  coke  needles. 

"I  have  endeavored  to  give  the  ovens  such  dimensions  as  are 
most  likely  to  facilitate  the  dissociation  of  the  hydrocarbon  gases, 
which  is  such  an  essential  part  in  the  method  of  carbonization 
just  described. 

"The  general  arrangement  of  the  condensing  apparatus  at  the 
mines  of  Campagnac  is  shown  in  Fig.  7,  which  gives,  at  the  same 
time,  their  connection  with  coke  ovens.  At  each  end  of  the  oven  bat- 
teries, a  boiler  is  heated  with  the  products  of  combustion  resulting 
from  the  heating  gases,  which  must  pass  under  the  boiler  on  their 
way  to  the  chimney.  These  boilers  work  alternately,  just  as  one  or 
the  other  chimney  takes  the  products  of  combustion.  Should  it, 
however,  be  found  necessary,  both  boilers  and  chimneys  can  be  used. 

"The  by-product-saving  apparatuses  are  as  follows:  Fig.  7, 
a,  expansion  regulating  tank;  6,  condenser;  c,  pipe  condenser; 
d,  e,  scrubbers;  /,  tar  condenser;  g,  exhauster. 

"These  apparatuses  work  in  the  manner  explained  below. 

"  (a)  This  expansion  regulating  tank  is  a  simple  cylinder  of 
sheet  iron,  4  feet  3  inches  in  diameter  and  16  feet  5  inches  high, 
standing  vertically.  The  gases  of  distillation  arrive  at  the  upper 
part,  through  the  collecting  pipe  n,  Fig.  7,  and  leave  the  cylinder 
at  the  lower  part.  Arriving  at  this  large  tank,  from  the  tube  n,  the 
gas  expands,  and  this  is  sufficient  to  cause  it  to  abandon  a  certain 
proportion  of  tar  and  ammoniacal  water.  The  temperature  of  the 


230  TREATISE  ON  COKE 

gas  in  this  reservoir  varies  with  the  external  temperature  and  the 
amount  of  gas  produced  by  the  ovens;  it  is  between  70°  and  90° 
centigrade  (158°  to  194°  F.).  The  pressure  on  the  contrary  remains 
constant  and  is  0. 

"  (6)  From  the  expansion  tank  the  gas  goes  to  the  square 
condenser — a  rectangular  tank,  6£  feet  high,  3  feet  4  inches  wide, 
and  3  feet  deep.  This  tank  is  placed  in  another,  open  at  the  top, 
of  1  foot  high,  4  feet  wide,  and  3  feet  7  inches  deep,  filled  with  water 
to  the  height  of  an  overflow,  which  permits  the  discharge  of  the 
condensed  liquids.  The  first  tank  is  divided  into  six  compartments 
by  vertical  hollow  partitions,  in  which  cold  water  circulates. 
These  partitions  are  so  arranged  that  the  gas,  in  order  to  circulate, 
must  pass  from  one  compartment  to  the  other  and  bubble  through 
the  condensation  water.  Traversing  this  apparatus  the  tempera- 
ture of  the  gases  falls  about  11°  to  13°  centigrade  (52°  to  55.4°  F.), 
and  they  lose  a  considerable  quantity  of  tar  and  ammoniacal 
water,  the  cooling  surface  of  the  tank  being  258  square  feet. 
Leaving  the  apparatus,  the  gases  have  attained  a  depression  of 
.08  to  .18  meter  (3J  to  7  inches)  of  water. 

"  (c)  From  the  square  condenser  the  gas  passes  through  the 
pipe  condenser — a  series  of  wrought -iron  serpentine  pipes,  water- 
cooled  from  the  top  by  a  water  spray.  The  condensing  surface  of 
these  pipes  is  1,115  square  feet,  the  decrease  of  temperature  20° 
to  26°  centigrade  (68°  to  79°  F.). 

"(d),  (e)  Two  scrubbers  follow  the  pipe  condensers;  they  are 
cylinders  of  3  feet  4  inches  diameter  and  16  feet  5  inches  in  height, 
and  contain  a  series  of  plates  so  arranged  that  the  gas  entering 
these  cylinders  at  the  bottom  meets  the  water  coming  from  the  top 
and  is  methodically  washed.  The  cylinders  are  filled  over  two- 
fifths  of  their  height  with  crushed  coke.  In  one  of  the  scrubbers, 
the  gases  are  washed  with  ammoniacal  waters  in  order  to  enrich 
the  latter,  in  the  other  with  pure  water  in  order  to  extract  as  much 
ammonia  as  possible.  After  the  first  washing,  the  depression  of 
the  gases  is  .15  to  .22  meter  (5  to  8|  inches)  of  water;  after  the 
second  washing  .20  to  .27  meter  (8  to  10J  inches).  The  first 
washing  lowers  the  temperature  10°  to  15°  centigrade  (50°  to 
59°  F.) ;  the  second,  5°  to  6°  centigrade  (41°  to  43°  F.). 

"  (/)  The  tar  condenser  is  built  according  to  the  principle  of 
Pelouze  and  Andouin,  and  is.used  in  large  gas  works  to  deprive  the 
gases  of  the  last  particle  of  tar  which  they  may  yet  hold.  It  con- 
sists of  a  series  of  metallic  curtains  arranged  vertically  one  behind 
the  other.  These  curtains  are  construced  of  pieces  of  wire  about 
J  inch  in  diameter,  placed  vertically  in  frames,  f  inch  apart.  Each 
curtain  is  placed  behind  the  other  in  such  a  manner  that  the  wire 
strings  of  one  correspond  to  the  space  between  the  wires  of  the 
other.  The  gas,  passing  these  obstacles,  is  subjected  to  a  succession 
of  shocks  that  cause  it  to  yield  up  the  last  particle  of  tar  it  contains. 
To  work  properly,  the  needed  depression  of  this  apparatus  must 


TREATISE  ON  COKE  231 

be  .04  to  .05  meter  (1|  to  2  inches)  of  water.  This  is  regulated  by 
augmenting  or  decreasing  the  passage  surface  of  the  gases.  The 
frame  bearing  the  series  of  metallic  curtains  is  enclosed  in  a  case 
on  three  sides.  On  the  fourth  side,  the  bottom,  the  seal  is  effected 
by  the  waters  of  condensation  and  the  tar.  By  raising  and  lower- 
ing this  frame  in  the  waters,  which  have  a  constant  level,  the  passage 
surface  of  the  gases  is  increased  or  diminished,  and  correspondingly 
the  depression  of  the  gases  is  increased  or  decreased. 

tl(g)  The  exhauster  is  of  Bourdon's  system,  exhausting  the 
gases  by  means  of  a  jet  of  steam.  The  force  of  the  same  can  be 
regulated  by  the  introduction  of  a  needle  in  a  conical  opening. 
The  exhauster  is  set  so  that  there  is  neither  pressure  nor  depression 
in  the  expansive  tank,  the  first  of  the  condensing  apparatus.  In 
this  way  a  slight  pressure  of  gas  is  maintained  in  the  ovens,  exclu- 
ding the  air  entirely.  The  exhauster  produces  a  total  depression  of 
.25  to  .30  meter  (10  to  12  inches)  of  water,  measured  before  the 
gas  enters  it;  it  leaves  the  exhauster  with  a  pressure  of  .08  to 
.10  meter  (3J  to  4  inches)  of  water. 

"We  have  just  seen  that  the  gas  is  drawn  through  the  condens- 
ing apparatus  by  the  exhauster,  with  a  depression  of  .25  to  .30  meter 
(10  to  12  inches)  of  water,  and  that  the  latter  forces  it  back  to  the 
special  burners,  already  described,  in  order  to  heat  the  ovens. 
With  the  coals  of  the  Company  of  the  Mines  of  Campagnac,  con- 
taining 35  to  36  per  cent,  of  volatile  matter,  it  was  thought  that  it 
would  not  endanger  the  perfect  operation  of  the  ovens  if  4,000  to 
5,000  cubic  feet  of  gas  were  taken  for  lighting  the  plant.  This 
gasometer,  of  2,119  cubic  feet  capacity,  is  placed  to  the  left  and 
back  of  the  ovens.  It  feeds  about  200  burners  distributed  over 
the  buildings  for  separating,  washing,  unloading,  etc.  The  gas- 
ometer is  filled  at  the  times  when  the  gas  production  is  greatest, 
that  is,  after  the  last  charge.  To  effect  this,  it  is  only  necessary 
to  shut  off  the  gases  from  going  back  to  the  ovens,  at  the  same  time 
establishing  communication  with  the  gasometer.  The  latter  is 
filled  in  a  few  minutes;  it  is  then  isolated  and  the  gas  from  the 
exhauster  goes  again  to  the  ovens.  The  whole  operation  takes  about 
7  to  8  minutes,  during  which  time  the  coke  ovens  are  not  disturbed. 
This  gas  for  illuminating  purposes  is  purified  by  lime  in  two  ordi- 
nary purifiers,  after  leaving  the  gasometer.  The  whole  plant  is 
thus  well  and  economically  lighted,  as  this  gas  costs  a  trifle. 

"The  products  of  condensation,  tar  and  ammoniacal  water,  as 
they  come  from  the  various  condensing  apparatuses  and  the  hydraulic 
main,  are  all  conducted  into  a  series  of  settling  tanks  where  the 
difference  in  density  permits  an  easy  separation.  The  tar  is  drawn 
off  by  a  hand  pump  and  put  into  barrels  direct,  ready  to  be  sent  to 
market.  The  ammoniacal  waters  are  taken  up  by  a  pump.,  driven 
by  a  steam  engine,  and  lifted  to  a  reservoir,  the  level  of  which  is 
higher  than  any  of  the  apparatus  of  the  plant.  From  this  reservoir 
these  waters  go  back  to  the  first  scrubber  to  be  concentrated. 


232  TREATISE  ON  COKE 

Manufacture  of  Sulphate  of  Ammonia. — 'The  distilling  appa- 
ratus for  the  treatment  of  ammoniacal  waters  is  a  modification  of 
the  apparatus  of  Mallet.  About  70^  cubic  feet  of  these  waters 
are  treated  at  a  time.  This  quantity  arrives  in  two  sheet-iron 
receivers,  which  are  placed  side  by  side  over  a  stone  pier,  in  order 
to  be  heated  at  the  same  time  in  the  same  heating  chamber.  Before 
heating,  a  small  quantity  of  lime  water  is  put  in  each  receiver. 
During  this  process,  which  lasts  about  4  hours,  the  mixture  is 
agitated  from  time  to  time  with  agitators  for  this  purpose,  and  the 
disengaged  gases  go  over  into  a  third  receiver  containing  70  cubic 
feet  of  ammoniacal  waters. 

"This  third  receiver  is  heated  by  the  return  flame  of  the  others 
and  also  by  the  vapors  of  ammonia  introduced  into  it.  These 
vapors  of  ammonia,  however,  disengage  themselves  as  soon  as  the 
temperature  becomes  high  enough,  and  are  conducted  into  lead 
tanks  that  contain  sulphuric  acid,  and  uniting  with  the  latter  yield 
sulphate  of  ammonia.  During  this  process  the  sulphuric  acid 
absorbs  also  the  steam  that  the  vapors  of  ammonia  carry  with 
.them.  The  sulphuric  acid  of  60°  uniting  with  the  water  yields  the 
sulphate  of  ammonia  in  solution.  The  solution  being  evaporated, 
a  white  salt,  sulphate  of  ammonia,  is  obtained  with  20  per  cent, 
of  nitrogen. 

"The  crystallization  is  effected  in  large  tanks  of  sheet  iron, 
lined  with  lead,  and  having  a  small  bottom.  These  tanks  are 
13  feet  2  inches  long,  5  feet  9  inches  wide,  and  1  foot  4  inches  deep. 
Two  of  these  permit,  with  a  crystallization  surface  of  55  square 
feet,  the  crystallization  of  660  pounds  of  sulphate  of  ammonia  in 
24  hours.  In  the  double  bottom  of  the  tank  steam  is  introduced, 
furnished  by  the  boilers  of  the  ovens.  Usually  660  to  770  pounds 
of  sulphuric  acid  of  60°  is  used,  and  a  weight  about  equal  to  that  of 
sulphate  of  ammonia  is  obtained.  The  work  is  very  easy;  a  single 
man  can  attend  to  the  manufacture  of  the  sulphate  of  ammonia 
that  40  to  50  tons  of  coal  will  produce.  This  is  the  quantity  that 
is  coked  daily.  A  boy  suffices  to  put  the  manufactured  tar  in 
barrels.  These  two  can  be  employed  besides  this  for  other  work. 

"Such  are  the  arrangements  of  the  works  of  the  Company  of 
the  Mines  of  Campagnac. 

"The  following  statements  show  the  cost  of  this  plant,  with  the 
expense  of  making  coke  and  saving  the  by-products: 

Cost  of  Plant — Nineteen  Coke  Ovens.     France 

Construction  of  nineteen  ovens $13,177.07 

Cost  of  each  oven,  $693.53 

Cost  of  condensing  plant 10,216.45 

Cost  of  apparatus— tar  and  ammonia 3,973.67 

Cost  per  oven — apparatus  for  by-products  of  tar 
and  ammonia— $746.85,  $1,440.38 


Total  cost  of  plant $27,367.19 


TREATISE  ON  COKE  233 

The  Work  of  Ovens  in  the  Year  1883  TONS 

Coal  charged  into  ovens   14,675 

Coke  produced ll,006i 

Showing  product  of  coke,  75  per  cent. 

Cost  of  labor  and  supplies  per  ton  of  coke  and  its  by-products  pro- 
duced, 73^  cents. 

NOTE. — The  cost  of  such  a  plant  in  the  United  States  would  be  about 
as  follows: 

Ovens,  each $1 ,000  to  $1,250 

Condensing  apparatus  per  oven 700  to       750 

Tar  and  ammonia  plant 325  to        350 

Making  the  total  cost  of  each  oven,  including  chemical  plant,  $2,025  to 
$2,350,  depending  on  localities.  In  France  the  cost  would  be  $1,700  per 
oven  and  apparatus. 

"The  question  may  now  be  raised,  if  this  mode  of  carbonization 
from  top  down,  giving  such  good  results  with  coals  rich  in  volatile 
matters,  may  also  be  applied  to  any  other  coals  that  will  coke. 
We  are  convinced  that  it  will  be  advantageous  to  coke  coal  con- 
taining the  24  to  25  per  cent,  of  volatile  matter.  The  coals  of 
Campagnac  contain  22  per  cent,  of  combined  carbon,  of  which 
50  per  cent,  remains  in  the  coke.  It  is  difficult  to  estimate  before- 
hand what  amount  of  the  combined  carbon  of  a  given  coal  will 
become  disengaged  and  unite  with  the  coke.  As  to  coals  having 
less  than  24  to  25  per  cent,  of  volatile  matter  and  yet  capable  of 
coking,  the  ovens  of  Campagnac  will  give  excellent  results,  if  used 
as  an  ordinary  oven,  dispensing  with  the  gas-condensing  and 
by-product-saving  plant.  In  fact,  they  will  always  be  better  than 
the  ordinary  ovens,  as  they  develop  fully  the  coking  qualities  of 
the  coal,  especially  if  communication  be  established  on  either  side, 
between  the  retort  proper  and  the  top  wall  flue  a.  This  commu- 
nication should  be  established  as  near  the  outside  as  possible,  at  g. 
Each  oven  will  thus  have  two  openings  through  which  the  gases 
of  distillation  are  emptied  into  the  top  wall  flue,  and  their  coming 
in  contact  with  air,  drawn  into  the  flue  by  the  depression  of  the 
chimney,  will  ignite  them.  If  the  doors  and  charging  holes  are 
hermetically  sealed  with  clay,  the  coking  process  will  proceed 
exactly  in  the  same  manner  as  if  the  ovens  were  heated  with 
purified  gas  from  the  condensing  plant.  As  the  carbonization  goes 
from  the  top  downwards  in  a  sealed  retort  that  has  only  two 
openings  for  the  gas  to  escape,  the  dissociation  of  the  gases  and 
deposits  of  part  of  their  combined  carbon  with  the  coke  is  exactly 
the  same  as  in  the  ovens  at  Campagnac.  As  it  is  easy  to  control 
the  amount  of  air  necessary  for  combustion,  and  all  the  gases  of 
distillation  yielded  by  the  charge  of  coal  are  forced  to  pass  through 
all  the  flues,  it  is  easily  understood  that  in  such  an  oven  the 
maximum  temperature  is  reached  which  the  volatile  matter  of  the 
coal  can  furnish. 


234  TREATISE  ON  COKE 

"We  can  also  arrange  a  group  of  mixed  ovens  for  carbonizing 
coals  of  20  to  25  per  cent,  of  volatile  matter,  and  save  the  by-prod- 
ucts of  only  a  number  of  the  ovens.  It  will  thus  be  seen  that  these 
ovens  give  better  results  than  many  other  systems,  especially 
when  coal  fairly  well  adapted  for  coking  is  used.  By  a  most  simple 
arrangement,  which  does  not  cause  any  additional  cost  in  the  con- 
struction of  the  ovens,  hot  air  can  be  introduced  into  the  combustion 
chambers  instead  of  cold  air.  We  would  always  recommend  this 
arrangement,  when  coals  not  rich  in  volatile  matter  are  carbonized. 
The  results  obtained  from  hot  air  have  been  entirely  conclusive." 

From  the  preceding  statements  of  the  cost  and  work  of  this 
coke  oven,  it  is  evident  that  it  is  well  designed  for  coking  coals 
inheriting  medium  volumes  of  volatile  combustible  matters,  secur- 
ing a  maximum  quantity  of  deposited  carbon  from  the  hydro- 
carbons evolved  in  coking.  As  previously  noted,  it  can  be  used  to 
full  advantage  in  the  manufacture  of  coke  without  the  saving  of 
by-products,  as  well  as  in  making  coke  with  the  saving  of  tar  and 
ammonia,  at  the  option  of  the  management. 

Through  the  courtesy  of  Mr.  Walter  M.  Stein,  metallurgical 
engineer,  of  Primos,  Pennsylvania,  we  present  in  Fig.  8  a  general 
plan  of  twenty-four  retort  coke  ovens  with  saving  of  by-products, 
with  the  following  description: 

"Each  oven  has  two  escape  pipes  a  by  means  of  which  the 
gases  reach  the  hydraulic  main  b  and  are  then  drawn  by  a  Beale 
exhauster  through  the  pipe  line  c  into  the  five  condensers  d,  con- 
sisting of  concentric  cylinders.  The  Beale  exhausters  are  provided 
in  duplicate  to  prevent  any  stoppage  of  the  plant;  each  one,  how- 
ever, is  sufficient  to  exhaust  the  entire  gas  of  the  twenty-four  ovens. 
From  the  Beale  exhauster,  the  gas  is  forced  through  the  scrubbers  /. 
Two  of  these  are  ordinarily  used  and  two  are  reserve  scrubbers. 
After  the  scrubbers  follows  the  steam  exhauster  g.  The  pipe  line  h 
conveys  the  gas  back  to  the  ovens  to  heat  the  same.  -  A  branch  con- 
nection is  used  to  fill  the  gas  holder  i,  which  has  a  capacity  of  52,000 
cubic  feet ;  this  gas  can  be  used  for  heating  or  illuminating  purposes. 
The  small  branch  pipes  k  of  the  pipe  line  h  take  the  gas  into  the  hori- 
zontal wall  flues  of  the  ovens,  the  gas  being  admitted  either  into  the 
top  flue  only  or  into  all  of  the  three  wall  flues.  The  boiler  /  is  heated 
with  the  waste  gases,  while  the  surplus  gas  may  also  be  used  for  this 
purpose,  m  is  the  chimney;  n,  three  steam  pumps;  p,  three  reserve 
pumps;  o,  the  pipe  line  to  take  the  products  of  condensation  to  the 
reservoirs  from  the  hydraulic  main ;  r,  the  pipe  line  from  the  condens- 
ers to  the  reservoir;  s,  the  windlass  for  raising  the  door  of  the  ovens; 
t,  t,  the  charging  larries;  u,  the  main  gas  flue;  and  v  the  ammonia 
machine  for  making  sulphate  of  ammonia.  If  the  gas  is  used  for 
illuminating  purposes ,  a  purifier  is  inserted  before  the  gas  holder,  x  is 
the  coke-discharge  side  of  the  ovens ;  w,  the  machine  side  where  pusher 
works ;  y  is  the  reservoir  for  tar,  and  z  the  reservoir  for  strong  water 
of  ammonia;  while  z*  is  the  reservoir  for  weak  water  of  ammonia." 


3^E^^^ 

Uh&Jl 


17303 — vi  FIG.  8.     GENERAL  PLAN  OF  TWENTY-FOUR  RETORT  COKE  OVENS,  WITH  SAVING  OF  BY-PROD' 


"","".,  _^ 


& 


1 


SEIBEL'S  SYSTEM.     WALTER  M.  STEIN,  METALLURGICAL  ENGINEER,  PRIMOS,  PENNSYLVANIA 


TREATISE  ON  COKE  235 

Otto-Hoffman  Retort  Coke  Oven. — In  the  manufacture  of  coke 
for  metallurgical  uses  the  main  effort  is  usually  directed  to  the 
production  of  hard-bodied  coke,  with  a  full  developed  cellular 
structure.  It  adds  materially  to  the  value  of  such  coke,  both  as 
regards  purity. and  calorific  vigor  in  the  blast  furnace,  to  cause 
as  large  a  deposit  of  carbon,  from  the  volatile  hydrocarbon  gases 
evolved  in  coking,  as  is  possible  from  the  quality  of  the  coal  used 
in  making  the  coke;  hence,  in  all  retort  coke  ovens,  two  special 
requirements  are  demanded,  the  saving  of  the  fixed  carbon  of 
the  coal  in  coking  and  the  securing  of  a  deposit  of  carbon  from  the 
evolved  gases. 

In  addition  to  these  points,  during  the  past  decade  much  atten- 
tion has  been  given  in  Germany,  France,  and  England  to  saving 
the  by-products  of  tar  and  sulphate  of  ammonia,  which  are  carried 
out  in  the  gases  during  the  process  of  coking  the  coal. 

The  initial  efforts  in  this  direction  were  greatly  retarded  by 
prejudices  against  the  quality  of  the  coke  produced.  It  is  quite 
probable  that  these  had  some  foundation,  as  the  early  retort  coke 
ovens  were  incomplete  in  their  operations  and  their  product  of 
coke  somewhat  below  the  standard  requirements.  Besides,  gas- 
house  coke  was  looked  upon  as  a  retort  coke  and  considered  inferior, 
as  it  was  in  fact,  for  metallurgical  uses,  as  compared  with  the  car- 
bon-glazed coke  from  the  beehive  ovens. 

The  recent  improvements  in  retort  coke  ovens  have  nearly,  if 
not  quite,  removed  some  of  these  objections,  and  retort-oven  coke 
is  now  afforded  an  unprejudiced  test  on  its  merits. 

In  the  European  countries,  with  agricultural  conditions  requir- 
ing concentrated  manures,  the  by-product  of  sulphate  of  ammonia 
has  become  a  valuable  adjunct  in  the  manufacture  of  coke,  with 
the  assurance  of  a  home  market  for  all  that  can  be  produced. 

In  the  United  States  of  America  the  conditions  requiring  the 
use  of  concentrated  manures  are  somewhat  different,  as  there  is 
still  a  large  proportion  of  virgin  soil  that  requires  little  manure; 
yet  in  many  sections  of  the  country  the  sulphate  of  ammonia 
could  be  used  to  advantage  by  the  agriculturists.  Just  how  far 
the  American  coke  manufacturers  desire  to  invest  in  by-product 
appliances  to  their  coke-oven  plants,  is  a  business  inquiry  demand- 
ing earnest  and  exhaustive  consideration.  In  the  presence  of  a 
gradually  approaching  time  when  the  use  of  the  secondary  qualities 
of  coking  coals  becomes  necessary,  it  is  evident  that  the  retort 
coke  ovens  will  come  into  more  general  use,  in  the  manufacture  of 
coke  for  blast-furnace  and  kindred  uses.  Many  of  these  ovens 
can  be  used  either  with  or  without  the  auxiliary  appliances  for 
saving  by-products. 

We  are  further  indebted  to  Dr.  C.  Otto  and  Company,  of 
Dahlhausen  on  the  Ruhr,  for  developing  the  Otto-Hoffman  retort 
coke  oven,  which  has  in  a  great  measure  removed  the  prejudices 
against  retort  coke  previously  noted. 


TREATISE  ON  COKE  237 

The  following  description  of  this  oven  is  taken  mainly  from 
the  paper  of  B.  Leistikow,  general  director  of  the  Wilhelmshuette,* 

The  coking  chambers  of  the  Otto-Hoffman  ovens  are  narrow 
chambers,  16  to  24  inches  wide,  33  feet  long,  and  5  feet  3  inches 
high  to  the  base  of  the  arch,  and  are  closed  at  both  ends  by  air- 
tight doors. 

The  construction  of  these  ovens  is  based  on  a  combination  of 
the  Siemens  regenerator  according  to  Hoffman,  with  the  ordinary 
Otto  oven  as  a  model,  to  which  a  large  number  of  improvements 
have  been  made. 

Fig.  9  exhibits  a  longitudinal  section  of  an  Otto-Hoffman 
coke  oven.  The  pushing  engine  is  on  the  side  a;  the  coke  is  dis- 
charged on  the  side  b,  where  it  is  cooled. 

There  is  no  direct  connection  between  the  coking  chamber  and 
the  side  flues.  In  the  covering  arch  there  are  three  openings  c, 
which  are  ports  for  charging  coal  into  the  ovens,  and  two  open- 
ings d  through  which  the  gases  evolved  in  coking  pass  off. 

Under  the  base  of  the  arch,  in  the  side  walls,  there  are  hori- 
zontal flues  e,  Fig.  10,  that  connect  the  entire  vertical  draft  system. 

The  base  flues  /  running  lengthwise  of  the  oven  between  the 
side  walls  g,  are  divided  into  two  equal  parts  h  and  i.  These  halves 
are  connected  with  regenerators  /,  /',  used  for  preheating  the  air 
necessary  for  the  combustion  of  the  gases.  To  each  half  of  these 
base  flues,  tuyere  pipes  k  and  k'  are  connected,  which  are  fed 
through  the  gas-supply  pipes  /  and  /'. 

The  regenerators  are  long,  latticed,  brick  flues,  running  across 
the  whole  coking  chambers.  They  are  connected  at  one  end,  by 
means  of  a  reversing  valve,  either  with  the  air-distributing  pipe  m 
of  the  condensation  plant  in  Fig.  11,  or  back  with  the  chimney. 

As  soon  as  the  oven  is  heated  and  the  coking  process  in  opera- 
tion, the  gases  evolved  escape  through  the  openings  d,  d  into  the 
supply  pipe,  similar  to  the  retorts  in  gas  plants,  and  thence  through 
the  opened  valve  into  the  gas  receiver,  from  which  they  pass  to 
the  condensation  plant.  From  the  latter,  the  gases,  freed  from 
their  by-products — tar,  ammonia,  and  benzol — are  returned  to 
be  burned  around  the  ovens.  On  the  way  to  the  latter,  is  a  revers- 
ing valve,  that  leads  the  gas  at  will  into  the  supply  pipe  /  or  /'. 

When  the  gas  enters  through  the  pipe  /  and  passes  through 
the  tuyere  k  by  means  of  the  cock  o,  into  the  half  h  of  the  base 
canal,  the  valve  is  so  set  that  blast  enters  the  flue  p  and  thence 
through  the  small  openings  q  into  the  regenerator  /  and  is  heated 
there,  passing  upwards  through  the  small  openings  r  into  the  base 
flue  h,  where  combustion  takes  place.  The  heated  products  of 
combustion  pass  through  the  side  vertical  flues,  then  to  the  hori- 
zontal flues  e  and  quickly  downwards  through  the  other  vertical 


*Address  delivered  on  September  5,  1892,  at  the  fifth  general  meeting 
of  the  German  Mining  Engineers. 


238 


TREATISE  ON  COKE 


half  to  the  base  flue  *,  thence  through  the  opening  r1  into  the  regen- 
erator /',  heating  it  and  passing  through  the  small  openings  q'  into 


the  flues  p •  p',  and  thence  through  the  air  valves  to  the  chimney. 
The  valve  is  reversed  after  a  certain  time,  and  the  gas  takes  exactly 
the  opposite  direction. 


TREATISE  ON  COKE 


239 


In  the  earlier  work  of  this  oven,  it  was  thought  necessary  to 
preheat  the  gas  as  well  as  the  air ;  for  this  purpose  a  second  regen- 
erator was  arranged  on  each  side  of  the  oven;  this,  however,  was 


discontinued,  as  it  was  found  to  be  better  to  heat  the  necessary 
air,  amounting  probably  to  ten  times  the  volume  of  the  gas,  to  a 
high  temperature,  than  to  heat  the  comparatively  small  volume 


240  TREATISE  ON  COKE 

of  gas,  thereby  running  the  risk  of  explosions.  In  all  later  plants, 
there  is  arranged  on  each  side  of  the  ovens,  only  one  regenerator, 
as  shown  in  the  accompanying  drawings,  by  which  change  this 
oven  has  been  much  simplified  without  impairing  its  utility. 

The  air  is  first  preheated  in  these  regenerators  to  about  1,000° 
centigrade,  thereby  reducing  the  amount  of  gas  necessary  to  heat 
the  ovens,  leaving  the  excess  for  other  purposes. 

The  gases  evolved  from  the  ovens  pass  through  the  valve  into 
the  receiver  and  are  aspirated  into  the  condenser  by  the  aspirator  5, 
Fig.  1 1 ;  on  its  way  to  the  condenser  the  gas  passes  into  an  appa- 
ratus /  wherein  it  is  cooled  and  separated  from  particles  of  coal 
dust  and  a  great  deal  of  the  tar. 

The  gases  now  pass  into  the  condenser  u,  consisting  of  a  verti- 
cal, four-cornered,  wrought-iron  box,  supplied  at  the  top  and  bot- 
tom with  false  floors,  on  which  are  arranged  a  large  number  of 
wrought-iron  tubes,  through  which  cold  water  flows.  The  gases 
travel  around  the  tubes  in  opposite  directions,  while  the  products 
of  condensation,  tar  and  ammonia,  continually  run  off  below. 
The  water  of  the  coal  passes  off  as  steam,  absorbing  about  50  per 
cent,  of  the  ammonia. 

After  the  gases  have  passed  the  cooler,  they  arrive  at  the  puri- 
fier v,  which  is  quadrangular,  and  the  gas  divides  itself  into  a 
number  of  tubes  that  are  immersed  in  water.  In  the  purifier  the 
gas  is  first  washed  with  pure  water  and  then  with  weak  ammonia 
water,  and  the  remainder  of  the  tar  is  separated.  The  apparatus 
is  so  constructed  that  the  water  flows  in  from  above  and  out  below 
continuously.  This  water,  together  with  the  condensed  products 
of  the  air  and  water  coolers,  passes  into  a  large  vat,  where  the  tar 
separates  by  virtue  of  its  specific  gravity. 

The  same  aspirator  can  be  used  for  forcing  out  the  last  par- 
ticles of  gas,  which  becoming  heated  several  degrees  by  the  sudden 
compression  must  be  passed  through  another  cooler  w  to  be  reduced 
to  a  minimum  temperature  13°  to  18°  centigrade. 

After  leaving  cooler  w,  the  gas  streams  below  into  the  bell 
washer  x,  where  it  is  distributed  among  a  number  of  bells,  which 
have  a  toothed  diaphragm  extending  under  the  water,  whereby 
it  receives  a  thorough  scrubbing.  The  washer  contains  four 
to  six  shelves,  one  under  another,  and  the  water  flows  from 
above  downwards,  the  gas  takes  the  opposite  direction  and 
always  is  driven  against  the  fresh  stream  of  descending  water, 
whereby  it  is  completely  separated  from  the  least  traces  of  tar 
and  ammonia. 

The  purified  gas  may  now  be  conducted  to  the  ovens  for  com- 
bustion, unless  it  is  desired  to  separate  further  products,  notably 
benzol,  which  is  done  in  some  works,  the  process,  however,  being 
secret. 

The  gas,  before  being  forced  into  the  pipes  /  and  I' ,  Fig.  9,  is 
led  through  a  small  reservoir,  which  acts  as  a  pressure  regulator, 


TREATISE  ON  COKE  241 

and  indicates  to  the  inspector  whether  the  pressure  is  constant, 
which  is  necessary  to  insure  constant  temperature  in  the  ovens. 
The  temperature  was  found  to  be  as  follows: 

DEGREES 
CENTIGRADE 

In  the  hearth  flue 1,200  to  1,400 

In  the  side  walls 1,100  to  1,200 

In  the  regenerators  at  the  beginning  of  the  air 

supply 1,000 

In  the  regenerators  at  their  ends 720 

In  the  chimney, 420 

The  tar  that  separates  at  the  bottom  of  the  vat  by  reason  of 
its  weight  is  conveyed  by  a  wall  pump  operating  a  spiral  con- 
veyer to  the  high  receiver  y,  Fig.  12,  from  which  it  may  be  run 
directly  into  cars  and  taken  to  the  refineries. 

The  ammonia  water,  which  has  collected  in  the  vats,  is  pumped 
to  the  receiver  z,  Fig.  13,  from  whence  it  is  piped  to  the  distilling 
room  of  the  ammonia  factory.  In  this  latter  are  two  Colonnen  appa- 
ratuses a,  a',  of  the  Grueneberg-Blum  system  (in  other  works  they 
use  Doctor  Feldmann's  apparatus  with  equally  good  results),  each 
capable  of  working  30,000  liters,  in  which  the  water  passes  down- 
wards from  column  to  column,  coming  in  contact  with  a  current 
of  dry  steam  which  takes  out  the  ammonia  and  carries  it  with  it. 
The  ammonia  is  set  free  from  its  compounds  by  milk  of  lime  in 
the  space  above  the  cascade  column,  which  is  pumped  into  the 
apparatus  from  the  lime  reservoir  b'. 

The  steam,  saturated  with  ammonia,  is  led  into  sulphuric  acid 
in  the  lead-lined  chambers  cr  where  it  is  converted  to  ammonium 
sulphate,  or  into  the  condenser  dr  where  it  is  taken  out  as  ammonia 
water.  When  the  chamber  acid  is  neutralized,  the  liquor  is  drawn 
off  and  the  salt  removed  to  the  dropping  board  z,  from  whence, 
when  the  lye  has  entirely  drained,  it  will  be  transferred  to  the 
lead-lined  salt  chambers.  On  the  other  hand,  if  the  ammonia 
water  is  simply  condensed  in  the  cooler  d' ,  it  runs  into  the  receiver  ef 
(holding  about  10  tons),  whence  it  may  be  piped  into  tank  cars 
for  transportation. 

The  sulphuric  acid  may  be  stored  in  the  receiver  /,  to  be  run 
off  by  means  of  air  pumps  or  siphons  as  needed,  into  the  boxes  c' . 
The  waste  water  that  runs  off  from  the  apparatus  a'  is  led  into 
vats,  where  the  lime  settles  out. 

The  plan  and  sections  in  Figs.  12  and  13  exhibit  a  view  of 
Plant  3  of  the  Julienhuette,  at  Buethen,  in  East  Silesia. 

The  cost  of  this  oven  and  the  distillation  apparatus  in  Germany 
is  as  follows: 

The  cost  of  oven $1,168.  75 

By-products  apparatus,  per  oven. 1,636.25 


Total $2,805.00 


242 


TREATISE  ON  COKE 


The  cost  would  be  largely  increased  in  the  United  States, 
especially  as  the  apparatus  for  the  saving  of  the  by-products  is 
erected  in  duplicate.  This  duplicate  apparatus  affords  the  oppor- 
tunity of  cleaning  and  repairing  the  several  parts  of  these  appli- 
ances without  interruption  to  the  continuous  work  of  the  ovens.  It 


adds  to  the  expense  in  the  construction  of  the  plant,  but  is  found 
to  be  an  element  of  economy  in  the  working  of  these  retort  ovens. 
The  Otto-Hoffman  oven  is  usually  constructed  in  sections  of 
sixty  ovens  each.  A  duplicate  apparatus  for  condensing  and 
exhausting  will  serve  for  two  sections  of  ovens. 


TREATISE  ON  COKE 


243 


The  cost  of  these  ovens  in  the  United  States  has  been  esti- 
mated at  $3,300  each.  This  includes  the  necessary  apparatus  for 
the  saving  of  the  by-products  of  tar  and  ammonia  sulphate,  but 
does  not  cover  the  patent  charge  for  using  this  oven. 


In  the  estimates  of  the  value  of 'the  by-products  secured,  per 
ton  of  coke  made,  very  large  claims  have  been  submitted.  With 
the  use  of  good  coking  coal,  the  net  profits  have  been  estimated 
as  high  as  $1.52  per  net  ton  of  coke  produced.  It  may  be  pointed 
out  that  this  estimate  includes  the  value  of  40  per  cent,  of  surplus 
gas  for  heating  purposes,  which  is  calculated  at  14  cents  per  ton 

10 


244  TREATISE  ON  COKE 

of  coke.  It  is  evident  that  such  an  estimate  is  misleading,  when 
it  is  considered  that  tar  is  now  worth  at  the  coke  ovens  $5  per 
ton,  and  ammonia  sulphate  $55  to  $60  per  ton  in  the  market. 

An  average  product  of  about  1  per  cent,  of  ammonia  sulphate 
and  3  per  cent,  of  tar  can  be  secured  from  the  carbonization  of 
coal  to  make  100  tons  of  coke.  Under  present  conditions  the 
value  of  these  at  the  coke  works  is  $50  and  $15,  making  in  all  $65, 
less  the  cost  of  manufacturing  the  sulphate  of  ammonia,  $34  per 
ton,  leaving  as  the  maximum  net  profit  per  100  tons  of  coke  made, 
$36;  or  36  cents  per  ton. 

The  value  per  ton  of  coke  of  surplus  gas  from  the  ovens  will 
be  somewhat  different,  depending  on  the  value  of  coal  in  the 
locality  of  the  coke  ovens.  An  average  of  5  cents  per  ton  would 
be  a  safe  estimate.  This,  added  to  the  value  of  the  by-products 
of  tar  and  ammonia  sulphate,  affords  a  net  saving  of  about  41  cents 
per  ton  of  coke  produced. 

A  reference  to  the  table  on  page  398,  Chapter  X,  will  afford 
full  details. 

Dr.  F.  Schniewind,  of  New  York  City,  who  represents  this  oven 
in  the  United  States,  writes: 

"As  to  the  life  of  the  plant,  the  construction  of  the  ovens  in 
all  details  is  most  substantial,  reducing  repairs  to  a  minimum. 
At  Hoerde,  Westphalia,  there  is  a  plant  making  coke  without 
saving  by-products,  that  has  been  running  the  past  13  years  and 
requiring  very  moderate  repairs.  The  coking  coal  used  in  Germany 
is  very  different  in  quality  from  the  American  standard,  the  Connells- 
ville  coal.  It  is,  as  regards  coking  qualities,  poorer  throughout. 

"  In  Westphalia,  in  the  Ruhr  basin,  the  most  important  coal  and 
coke  district  in  Germany,  the  coal  varies  in  its  character  in  a  sim- 
ilar way  as  in  the  Appalachian  field;  the  coal  becoming  more 
bituminous  in  a  gradual  increase  from  the  east  to  the  west.  This 
gives  a  variety  of  qualities  of  coal  for  coking,  depending  on  the 
locality  of  the  coal  supply.  The  yield  of  coke  varies  from  70  to 
85  per  cent,  of  coal  charged  into  ovens. 

"The  following  may  be  considered  an  average  analysis  of  West- 
phalian  coking  coal  washed: 

PER  CENT. 

Volatile  matter 23 . 00 

Fixed  carbon 67 . 70 

Ash 8 . 00 

Sulphur -:.. .  •    1.30 

"The  theoretic  yield  of  coke  would  be  about  76.48  per  cent. 
The  washed  coal  is  charged  into  the  ovens  in  a  very  moist  condition, 
holding  about  12  per  cent,  of  water.  The  coke,  though  it  cannot 
be  compared  as  to  luster  with  the  Connellsville  coke,  is  an  excellent 
blast-furnace  fuel,  which  stands  a  heavy  burden  in  the  furnace. 

"The  fuel  results  of  the  German  blast  furnace  are  very  good 
indeed  if  the  poor  quality  of  the  coke-making  coals  is  considered. 


TREATISE  ON  COKE  245 

"In  Silesia,  the  coking  coal  is  of  very  poor  quality.  In  some 
instances,  extraordinary  measures  have  to  be  resorted  to  in  order 
to  produce  coke;  the  coal  has  to  be  disintegrated  finely  and  then 
while  moist  stamped  by  hand  into  large  sheet-iron  casks  and 
charged  into  the  ovens.  It  is  only  in  this  way,  and  by  the  use  of 
the  Otto-Hoffman  ovens  at  a  very  high  temperature,  that  a  coke 
suitable  for  blast-furnace  use  can  be  made. , 

"  In  the  Saar  district  the  coal  is  also  very  poor. " 

Test  of  the  Connellsville  Coal  in  the  Otto-Hoffman  Ovens. — In 

order  to  investigate  the  results  that  might  be  expected  from  these 
ovens  when  running  on  Connellsville  coal,  I  went  over  to  Europe 
early  in  the  summer  of  1893,  in  the  company  of  a  competent  Amer- 
ican blast-furnace  engineer,  who  was  sent  by  some  capitalists  who. 
had  become  interested  in  this  matter. 

We  had  sent  to  Europe  about  18  tons  of  Connellsville  coal, 
with  which,  after  some  preliminary  tests,  we  charged  whole  ovens. 
The  coke  made  was  of  most  excellent  quality,  very  hard,  with 
metallic  ring  and  silvery  luster. 

Some  of  this  coke  was  placed  on  exhibition  in  the  mining  expo- 
sition at  Gelsenkirchen,   where  it  caused  general  admiration,   as 
not  a  single  brand  of  Westphalian  coke  could  compare  with  it. 
The  Connellsville  coal  was  composed  as  follows: 

PER  CENT. 

Moisture 1 .  59 

Volatile  matter « 29 . 18 

Fixed  carbon 58 . 84 

Ash 9.40 

Sulphur 99 

Total 100.00 

The  theoretic  yield  of  coke  from  the  above  coal  is  about  68.84 
per  cent.;  in  the  Otto-Hoffman  ovens  the  products  were: 

PER  CENT. 

Large  coke 71.1 

Small  coke 1.2 

Breeze..  1.3 


Total 73.6 

This  result  shows,  assuming  that  no  fixed  carbon  has  been 
burned  in  coking,  a  deposit  of  4.76  per  cent,  of  carbon  from  the 
hydrocarbons  in  coking.  The  result  is  evidently  correct,  as  the 
rich  coking  coals  of  Connellsville  or  West  Virginia  secure  carbon 
deposits  in  the  coke  oven. 

The  time  occupied  in  coking  Connellsville  coal  in  the  Otto- 
Hoffman  oven  was  from  28  to  32  hours. 

As  to  the  yield  of  by-products,  the  Connellsville  proved  to  be 
equal  to  the  richest  German  coals,  as  will  be  seen  from  the  following 
figures  based  upon  dry  coal: 


246 


TREATISE  ON  COKE 


Locality 

Coke  and  Breeze 
Per  Cent. 

Tar 
Per  Cent. 

Sulphate  of 
Ammonia 
Per  Cent. 

Cubic  Feet  Gas, 
Per  Net  Ton 
of  Coal 

Connellsville  coal  .  . 
Westphalian  coal  .  . 
Silesian  coal  .... 

73.6 
76.0 
67.0 

4.0 

30 
4.2 

1.07 

1.15 

1.12 

9,321 
8,744 
10,057 

In  regard  "to  benzol,  the  yield  from  Connellsville  coal  will  be 
found  richer  than  that  from  German  coals,  which  yield  from  .3  to 
.7  per  cent,  from  dry  coal.  It  is  difficult,  however,  to  make  any 
accurate  statement,  as  analytical  research  is  insufficient.  The 
quality  of  the  by-products  obtained  from  Connellsville  coal  was 
excellent. 

The  excess  of  gas,  about  40  per  cent,  of  the  total  production, 
is  of  great  value  for  illuminating  and  heating  purposes.  As  a 
source  of  light,  it  has  only  about  one-half  the  illuminating  power 
of  best  illuminating  gas,  if  used  with  ordinary  burners ;  but  if  used 
with  the  modern  incandescent  burners,  its  light  equals  in  brilliancy 
the  electric  incandescent  lamp.  The  fuel  value  may  be  judged 
from  the  following  comparative  table: 

TABLE  OF  ANALYSES  OF  DIFFERENT  GASES 


Percentage  by 
Volume 

Gas 

From 
Otto- 
HorTman 
Ovens 

1 

Coal  Gas, 
Average 
American 

2 

Coal  Gas, 
Cologne, 
Germany 

3 

Natural 
Gas 

4 

Water 
Gas 

5 

Producer  Gas 

Gas 
From 
Im- 
proved 
Bee- 
hive 
Ovens 
8 

An- 
thra- 
cite 
6 

Bitu- 
min- 
ous 

7 

Hydrogen.  .... 
Methylene  
Ethylene 

53.32 
36.11 
1.63 
.61 
6.49 
1.41 
.43 

46.0 
40.0 
4.0 

? 

6.0 
.5 

? 

i.5 

.5 
1.5 

55.00 
36.00 
1.19 
1.54 
5.40 
.87 
? 

2.18 
92.60 
.31 

.50 
.26 

3.61 
.34 

45.0 
2.4 

45.0 
4.0 

2.0 
.5 
1.5 

12.0 

1.2 

270 
2.5 

57.0 
.3 

12.0 
2.5 
.4 

27.0 
2.5 

56.2 
.3 

23 

13.7 
.9 

2  6 
98 

70.0 

.7 

Benzol  
Carbon  monoxide 
Carbon  dioxide  .  . 
Sulph.  hydrogen 
Nitrogen  

Oxygen  
Vapor  

100.00 

100.0 

100  .  00 

99.80 

100.4 

100.0 

100.9 

100.0 

Analyses  1  and  3,  by  Doctor  Knublanch;  2,  4,  5,  6,  7,  by  W.  J. 
Taylor,  A.  I.  M.  E.,  Vol.  XVIII,  page  881;  No.  8,  by  the  agents 
of  the  English  or  Smith  oven. 

The  comparison,  especially  of  the  percentage  of  nitrogen,  will 
show  the  efficiency  of  the  Otto-Hoffman  oven. 

At  most  plants  the  surplus  gas  is  used  for  generating  steam  in 
boilers,  together  with  the  off  heat  from  the  regenerators.  The 


TREATISE  ON  COKE 


247 


248 


TREATISE  ON  COKE 


steam  produced  is  .9  pound  of  four  to  five  atmospheres  pressure 
for  each  pound  of  dry  coal  coked  in  the  ovens.  This  is  the  average 
result  of  48  hours  run  (if  the  time  of  coking  is  reduced,  the  evapo- 
ration of  water  increases)  and  after  all  the  by-products,  including 
benzol,  have  been  recovered. 

Tar  has  found  two  principal  uses  in  addition  to  its  former 
applications.  The  manufacture  of  tar  paper  utilizes  a  fair  pro- 
portion of  this  product;  the  coming  briquet  industry  will  in  the 
future  greatly  enlarge  the  demand  for  tar. 

The  market  for  the  by-products  of  tar  and  the  sulphate  of 
ammonia  is  reported  as  fairly  good,  with  an  upward  tendency. 


FIG.  15.     OTTO-HOFFMAN  BY-PRODUCT  PLANT,  OTTO  STATION,  PENNSYLVANIA 

The  demand  for  tar  has  been  increased  by  the  change  in  the 
methods  of  making  illuminating  gas  at  the  gasworks. 

It  is  submitted  that  Philadelphia,  Cleveland,  and  Chicago  afford 
a  good  market  for  these  by-products. 


OTTO-HOFFMAN  COKE  OVENS  AND  BY-PRODUCT  APPARATUS  OF  THE 
PITTSBURG  GAS  AND  COKE  COMPANY* 

This  plant  is  shown  in  plan  in  Fig.  14  and  a  photograph  of 
it  in  Fig.  15.  The  ovens,  built  in  four  sets  of  thirty  each, 
are  arranged  symmetrically  on  two  sides  of  the  coal-storage 
building.  The  two  portions  of  the  coking  plant  being  dupli- 
cates, only  one  of  them  will  be  described.  Between  the  two 
sets  of  ovens  constituting  one-half  of  the  plant  is  a  25-foot 

*W    L.  Affelder  in  Mines  and  Minerals,  February,  1899. 


TREATISE  ON  COKE  249 

space  containing  four  Cahall  vertical  boilers  of  100-horsepower 
capacity  each,  while  in  the  similar  space  in  the  other  half  of  the 
plant  there  is  one  200-horsepower  Babcock  &  Wilcox  boiler. 
Their  combined  capacity  is  450  horsepower,  and  they  furnish 
all  the  steam  power  needed  at  the  plant.  Each  oven  is  33  feet 
long,  6  feet  high,  and  22  inches  wide,  with  12-inch  walls.  The 
ovens  are  built  of  sandstone  and  are  lined  with  firebrick.  Through 
the  arched  roof  there  are  five  circular  openings,  three  being  for  the 
introduction  of  coal,  and  the  other  two  for  the  egress  of  the 
volatile  materials.  The  ends  are  covered  with  cast-iron  doors 
that  are  raised  or  lowered  by  means  of  a  portable  windlass  on  the 
top  of  the  oven.  Directly  below  the  oven  floor  extends  a  narrow, 
brick-lined  flue  crossed  midway  between  the  ends  by  a  transverse 
partition.  This  flue  communicates  with  the  vertical  flues  in  the 
side  walls,  which  are  joined  at  the  top  of  each  wall  by  a  narrow, 
horizontal  flue.  Beneath  the  ends  of  the  ovens  and  extending 
along  the  entire  set  are  Siemens'  regenerators. 

Each  oven  is  charged  through  the  openings  in  the  top  with 
7  tons  of  coal,  crushed  to  ^  inch  and  less.  A  stream  of  gas  that 
has  been  recovered  as  a  by-product  from  coal  that  has  been  pre- 
viously coked  is  introduced  at  one  end  of  the  flue  that  extends 
beneath  the  floor  of  the  oven  through  a  2-inch  pipe.  Here  it 
meets  air  that,  by  passing  through  the  heated  regenerator,  has  a 
temperature  of  about  2,000°  F.  The  influx  of  air  is  accelerated  by 
a  fan  situated  in  the  space  between  the  two  sets  of  ovens.  The 
hot  air  and  burning  gas  pass  through  the  horizontal  flue  and  up  the 
vertical  flues  of  the  front  half  of  the  oven  into  the  horizontal  flue 
near  the  top  of  each  wall.  They  then  pass  down  the  other  vertical 
flues  and  out  through  the  bottom  horizontal  flue  of  the  rear  half  of 
the  oven  into  the  second  regenerator.  After  passing  through  the 
second  regenerator  the  gases  are  still  very  hot,  and  a  portion  of 
their  heat  is  utilized  in  the  boilers  before  they  are  allowed  to  pass 
up  the  chimney.  The  heat  imparted  to  the  coal  by  the  highly 
heated  floors  and  walls  drives  from  it  all  the  volatile  matter,  and 
at  the  end  of  from  24  to  36  hours,  the  time  depending  principally 
on  the  nature  of  the  coal,  a  mass  of  red-hot  coke,  weighing  from 
75  per  cent,  to  78  per  cent,  of  the  weight  of  the  coal  charged,  is 
removed  from  the  oven  by  means  of  a  steam  ram. 

Recovery  of  the  By-Products.— Although  many  of  the  German 
plants  recover  tar,  gas,  ammonia,  and  benzol,  no  attempt  is  made 
at  this  plant  to  separate  the  latter  from  the  tar. 

Extending  along  the  top  of  each  set  of  ovens  and  sloping  at  a 
small  angle  toward  the  space  between  the  two  sets  of  ovens  are 
two  24-inch  cast-iron  pipes,  called  tar  pipes,  into  which  the  volatile 
matter  passes  through  double-elbowed  pipes  extending  from  two 
openings  in  the  top  of  each  oven.  The  elbows  are  intended  to 
catch  the  greater  portion  of  the  soot .  thereby  preventing  its  being 


250  TREATISE  ON  COKE 

collected  with  the  tar.  A  third  pipe,  18  inches  in  diameter,  between 
and  above  the  other  two,  communicates  with  both  of  them  near 
their  ends  in  order  to  equalize  the  pressure,  which  would  otherwise 
differ  greatly  because  of  the  suction  applied  at  their  lower  ends  to 
accelerate  the  flow  of  their  contents.  The  several  tar  pipes  unite 
to  form  one  36-inch  main,  which  discharges  its  contents  into  a 
bottomless  tank,  with  its  lower  part  immersed  in  tar.  Almost  all 
the  tar  separates,  by  virtue  of  its  specific  gravity,  from  the  gases 
with  which  it  is  mixed,  and  flows  in  a  slow,  but  steady,  stream 
into  a  brick-walled  cistern  100  by  20  feet,  while  the  gases  pass  into 
the  condensing  house  directly  beyond  this  cistern. 

The  gases  pass  up  through  three  tall,  cylindrical,  sheet-iron 
washing  tanks,  in  which  sprays  of  cold  water  wash  out  most  of 
the  tar  still  present,  together  with  a  considerable  portion  of  the 
ammonia.  The  gases  are  then  led  through  several  cooling  tanks, 
which  are  nearly  filled  with  pipes  containing  circulating  water. 
Three  small  washers,  or  scrubbers,  are  next  employed  to  remove 
the  last  traces  of  tar  and  almost  all  the  remaining  ammonia.  The 
gases,  which  now  consist  of  the  ordinary  coal  gas,  with  a  very 
small  percentage  of  ammonia,  are  run  through  compressors  in 
order  that  the  pressure  will  meet  the  requirements  of  Wood's  mill, 
in  McKeesport,  to  which  the  gas  is  piped.  After  having  been  com- 
pressed, the  gases  are  again  cooled  and  washed,  this  final  washing 
taking  out  the  remaining  traces  of  ammonia.  Besides  being  used 
in  McKeesport,  the  gas  is  used  at  the  coking  plant  both  for  heating 
the  ovens  and  for  illuminating  purposes. 

The  tar  is  pumped  from  the  cistern  into  a  large  storage  tank, 
from  which  it  is  run  into  tank  cars  and  shipped  to  refineries.  Since 
all  the  water  employed  in  washing  the  gases  is  run  into  the  tar 
cistern,  the  ammoniacal  liquor  must  be  pumped  continually  from 
above  the  tar  into  a  storage  tank,  in  order  to  prevent  its  being 
carried  away  with  the  tar.  From  the  ammonia  tank,  the  liquor 
flows  through  pipes  to  the  ammonia  house,  which  adjoins  the  gas- 
washing  plant.  It  is  introduced  at  the  top  of  two  cylindrical, 
cast-iron  tanks,  together  with  lime  water,  while  a  jet  of  steam  is 
admitted  at  the  bottom.  The  heat  supplied  by  the  steam  acceler- 
ates the  liberation  of  ammonia  gas,  caused  by  the  lime  uniting  with 
the  acid  radical  of  the  various  ammonia  salts  present.  The  excess 
of  steam  carries  off  the  ammonia  as  NH£)H,  through  a  pipe  at  the 
top  of  each  tank.  The  ammonia  then  passes  into  vats  containing 
hot  sulphuric  acid,  in  which  the  following  reaction  takes  place: 

2NH4OH  +  H.2SO4  =  (NH4)2SO4  +  H2O 

When  the  solution  becomes  saturated  with  ammonium  sulphate, 
the  latter  settles  to  the  bottom  of  the  vats  and  is  removed  by 
means  of  perforated  ladles,  and  is  dried  in  a  centrifugal  dryer. 
A  small  portion  of  the  ammonia  is  sold  as  aqua  ammonia,  instead 
of  converting  it  into  the  sulphate. 


TREATISE  ON  COKE  251 

Not  only  does  the  company  obtain  a  greater  yield  of  good  coke 
than  is  obtainable  from  the  same  coal  when  used  in  beehive  ovens, 
but  it  also  obtains  a  large  quantity  of  valuable  by-products. 
According  to  the  statement  of  the  superintendent  of  the  plant,  the 
yield  of  coke  varies  from  75  per  cent,  to  78  per  cent. ;  of  tar,  5  per 
cent,  to  6  per  cent.;  of  ammonium  sulphate,  1.25  per  cent,  to 
1.45  per  cent.;  and  the  amount  of  gas  is  10,000  cubic  feet  per  ton 
of  coal.  He  also  stated  that  a  number  of  the  consumers  of  the 
coke  made  at  the  plant  preferred  it  to  that  made  in  the  Connells- 
ville  region.  The  fact  that  the  coke  finds  a  market  as  far  west  as 
Kansas  City,  Missouri,  speaks  well  for  its  quality.  That  the 
by-products  are  of  superior  quality  is  shown  by  the  large  and 
ready  market  for  them. 

A  few  words  might  well  be  said  in  this  connection  by  way  of 
comparing  the  relative  merits  of  the  Otto-Hoffman  and  the  beehive 
oven  as  coke  producers.  It  has  been  shown  by  actual  experiment 
that  the  yield  from  Connellsville  coal  in  an  Otto-Hoffman  oven  was 
73.6  per  cent.,  while  the  theoretic  yield  was  only  68.84  per  cent. 
The  United  States  Geological  Survey  reports  show  the  actual  yield 
from  the  beehive  ovens  in  the  Connellsville  region  to  have  been 
but*66.84  per  cent,  in  the  years  1880  to  1896,  inclusive.  Even  at 
the  lower  limit  claimed  by  the  superintendent,  the  company  is 
obtaining  from  its  ovens  an  amount  of  coke  exceeding  the  amount 
that  it  could  obtain  from  beehive  ovens  by  more  than  8  per  cent, 
of  the  weight  of  the  coal  charged. 

Eight  men  in  two  shifts  of  12  hours  each  are  employed.  The 
-total  coal  consumption  is  between  600  and  700  tons  per  day. 

I  am  indebted  to  Mr.  Wm.  L.  Elkins,  Jr.,  President  of  the 
United  Coke  and  Gas  Company,  and  to  Mr.  W.  P.  Parsons,  Super- 
intendent of  the  Pittsburg  Gas  and  Coke  Company,  through 
whose  courtesy  I  was  enabled  to  make  a  careful  study  of  the  plant. 


SCHNIEWIND  OVEN 

Description  of  a  Plant  of  100  Coke  Ovens.* — In  order  to  adapt 
the  Otto-Hoffman  process,  as  practiced  in  Germany,  to  the  new 
requirements,  it  has  had  to  undergo  many  changes.  I  will  describe 
a  plant  consisting  of  one  hundred  by-product  coke  ovens  of  the 
latest  type  of  the  United  Coke  and  Gas  Company.  (See  Fig.  16.) 

Ovens. — The  ovens  are  arranged  in  two  groups  of  batteries  of 
fifty  ovens  each.  Each  oven  a  is  an  air-tight  retort,  consisting  of  a 
rectangular  chamber  43  feet  6  inches  long,  17  inches  wide,  and 
6  feet  6  inches  high.  The  ovens  are  placed  side  by  side,  and  are 
supported  on  a  steel  structure,  consisting  of  light  I  beams,  running 
the  length  of  the  battery,  that  rest  on  cross-girders  supported  by 
steel  columns.  (United  States  patents  Nos.  627,595,  644,368, 

*Article  by  Dr.  F.  Schniewind. 


TREATISE  ON  COKE  253 

644,369,  668,225,  673,928.  British  patents  Nos.  13,325,  1899; 
3,335,  1900;  10,589,  1900;  993,  1901.  Further  patents  pending.) 

The  construction  allows  the  brickwork  to  be  inspected  at  all 
points.  The  primary  object,  however,  is  the  uniform  distribution 
of  fuel  gas  to  the  combustion  chambers  for  heating  the  oven 
retorts.  The  retorts  are  separated  by  hollow  walls  that  are  divided 
into  ten  compartments  b,  each  compartment  containing  four, 
preferably  vertical,  flues  c.  An  air  chamber  d  is  located  directly 
under  the  retort.  Alongside  this  chamber  and  directly  under  the 
vertical  flues  above  referred  to  are  ten  combustion  chambers  e. 
The  gas  supply  to  each  of  the  chambers  is  controlled  independently, 
and  a  uniform  heat  is  maintained  throughout  the  entire  length  of 
the  oven.  The  air  for  combustion  is  admitted  through  openings  / 
in  the  wall  between  the  air  and  the  combustion  chambers.  The 
air  is  heated  to  1,800°  F.  by  a  pair  of  regenerators  g  placed  together 
under  the  center  of  the  battery  and  running  its  entire  length. 
A  vertical  flue  h  conducts  the  air  from  the  regenerator  to  the  air 
chamber  d  under  the  oven. 

The  well-known  Siemens  principle  is  used  in  operating  the  air 
regenerators,  with  reversals  every  30  minutes.  The  fuel  gas  is 
reversed  at  the  same  time  as  the  air  by  means  of  a  suitable  valve; 
but  the  gas  is  not  regenerated.  The  gas  unites  with  the  hot  air  in 
five  combustion  chambers  e,  ascends  through  the  vertical  flues  c  to 
a  horizontal  flue  i  above,  through  which  it  passes  and  descends 
through  the  five  chambers  in  the  other  end  of  the  oven,  thence 
through  the  air  chamber  d  and  vertical  flue  connection  h  to  the 
regenerator  g,  and  through  the  reversing  valves  to  the  stack.  The 
regenerators  are  built  entirely  independent  of  the  oven  structure, 
so  that  their  expansion  does  not  affect  the  oven  brickwork. 

Coal  Handling. — A  steel  coal-storage  bin  of  a  capacity  equivalent 
to  about  2  days'  coal  consumption  is  placed  between  the  batteries. 
The  coal  is  elevated  to  the  bin  from  a  hopper  placed  under  the 
coal-receiving  track  by  a  belt  or  other  type  of  conveyer.  A  coal 
larry  of  8  tons  capacity  runs  on  a  track  on  the  top  of  the  batteries 
and  under  the  coal  bin.  The  larry  consists  of  a  long,  narrow  bin 
with  eight  spouts  in  the  bottom,  through  which  the  coal  is  run 
into  the  oven  retort  through  holes  in  the  top  of  it,  and  is  leveled 
by  means  of  a  bar  worked  through  a  small  opening  in  the  doors 
at  the  ends  of  the  oven.  The  larry  is  operated  by  an  electric 
motor  and  receives  its  load  of  coal  from  the  storage  bin,  under 
which  it, passes.  A  very  dense  metallurgical  coke  can  be  pro- 
duced and  the  output  of  an  oven  largely  increased  by  compressing 
the  coal  into  a  mold  slightly  smaller  than  the  retort  and  charging 
the  mass  through  the  oven  door. 

Coke  Handling. — On  the  completion  of  the  coking  process,  the 
oven  doors  are  raised  and  the  mass  of  6  tons  of  coke  is  pushed 
on  to  a  movable  platform  by  means  of  a  ram.  The  pushing  ram, 
as  well  as  the  machine  on  which  it  is  mounted,  are  operated  by 


254  TREATISE  ON  COKE 

electric  motors.  The  coke,  after  being  pushed  upon  the  platform, 
is  quenched  and  allowed  to  cool.  The  platform  is  then  tilted  by 
an  electric  motor  and  the  coke  slid  off  into  cars  that  run  on  a  track 
at  the  back  of  the  machine. 

Gas  Mains. — The  gas  distilled  from  the  coal  during  the  coking 
process  is  conducted  to  the  condensing  house  by  two  independent 
systems  of  mains  that  run  on  top  of  the  battery  the  entire  length, 
one  on  each  side.  Each  oven  is  connected  to  each  main  by  a  ver- 
tical pipe  and  valve. 

During  the  first  part  of  the  process,  the  rich  gas  is  taken  off 
through  the  rich-gas  main.  The  valve  to  this  main  is  then  closed 
and  the  balance  of  the  gas  is  taken  off  through  the  poor-gas  main. 
When  the  coking  is  completed,  the  valve  to  the  poor-gas  main  is 
closed,  disconnecting  the  oven  from  both  mains. 

Condensing  Plant. — The  gas  leaving  the  coke  ovens  is  divided 
into  two  fractions;  viz.,  the  first  fraction  or  rich  gas,  which  is 'sent 
out  as  illuminating  gas,  and  the  second  fraction  or  poor  gas,  which 
is  used  for  heating  the  ovens.  The  cooling  of  the  gas  and  the 
removal  of  tar  and  ammonia  are  done  in  the  usual  apparatus; 
hence,  it  is  not  necessary  to  discuss  it  here  in  detail.  Both  the  rich 
and  poor  gases  are  treated  in  the  same  manner.  The  following  is 
the  sequence  of  the  apparatus  as  shown  in  the  general  sketch  of 
a  gas  plant  for  coke  ovens,  Fig.  17:  a,  a'  are  air  coolers;  b,  b'  are 
multitubular  water  coolers;  c,c'  are  tar  extractors;  d,  df  are 
exhausters;  e,e'  are  second  coolers  intended  to  remove  the  heat 
produced  by  the  compression  of  the  gas  in  the  exhausters;  and 
/,  /'  are  ammonia  washers. 

The  rich  gas  when  freed  of  tar  and  ammonia  leaves  the  con- 
densing plant  and  passes  through  pipe  g  into_the  purifying  plant  h, 
and  from  there  into  a  large  storage  gas  holder  for  illuminating 
gas,  from  which  it  goes  into  the  city.  The  poor  gas,  after  being 
treated  in  the  same  manner  as  the  rich  gas,  leaves  the  ammonia 
washers  /  and  passes  through  two  benzol  scrubbers  i,  ir.  After 
having  been  freed  of  its  benzol,  it  flows  through  pipe  /  into  the 
oven-gas  holder  k.  Here  it  is  mixed  with  producer  gas,  when 
necessary,  which  will  be  discussed  later,  and  carried  to  the  ovens 
for  heating  by  the  pipe  /.  The  benzol  extracted  from  the  poor 
gas  is  then  transferred  to  the  rich  gas,  so  as  to  increase  its 
candlepower. 

The  tar  oil  by  which  the  gas  is  washed  runs  first  from  tank  n, 
through  the  second  benzol  scrubber  i,  into  tank  m.  From  here 
it  is  supplied  by  pump  m'  into  the  first  benzol  scrubber  i.  The  tar 
oil  enters  from  tank  n  with  about  5  per  cent,  of  benzol,  and  finally 
leaves  washer  i  with  about  15  per  cent,  of  benzol.  It  is  collected  in 
tank  o.  From  here  it  is  fed  by  pump  o'  into  still  /?,  in  which  the 
benzol  is  reduced  again  to  about  5  per  cent.  The  exhausted  oil  col- 
lects in  tank  q.  From  here  it  is  taken  by  pump  qr  through  the  oil 
cooler  r,  in  order  to  be  again  supplied  to  tank  n  for  a  new  absorption. 


256  TREATISE  ON  COKE 

The  Utilization  of  the  By-Products  of  the  Coke  Industry. — The 

following  valuable  paper  of  Dr.  Bruno  Terne  was  read  before  the 
chemical  section  of  the  Franklin  Institute,  Philadelphia,  Pennsyl- 
vania, October  20,  1891.  It  exhibits  Doctor  Otto's  efforts  in  utili- 
zing the  beehive  type  of  coke  oven  for  saving  the  by-products  of 
tar  and  ammonia. 

"About  a  year  ago  I  had  the  honor  to  speak,  in  the  lecture 
course  of  the  Franklin  Institute,  on  ammonia,  its  sources  and 
technical  uses.  I  dwelt,  for  reasons  that  I  thought  of  sufficient 
importance,  especially  on  the  production  of  ammonia  as  a  by- 
product of  the  coke  industry. 

"We  have  now  entered  on  the  beneficial  workings  of  the  new 
policy  of  furthering  industrial  developments  in  new  branches  in  a 
period  that  requires  the  technical  men  in  all  branches,  and  especially 
in  the  chemical  industries,  to  call  the  attention  of  the  capitalists  to 
the  points  in  which  we  are  behind  the  times  in  our  developments,  to 
the  points  where  the  resources  of  our  own  land  are  neglected,  and 
we  are  far  behind  the  more  progressive  European  manufacturers. 

"I  thought  it  of  sufficient  importance  to  ventilate  the  same 
question  before  the  chemical  section  of  the  institute  in  order  to 
create  an  interest  in  the  circle  of  the  members  of  the  institute,  who 
are  the  best  judges  of  such  questions,  in  order  to  provoke  criticism 
of  my  views.  I  have  revised  the  part  of  my  lecture  referring  to  the 
development  of  the  ammonia  industry  for  this  purpose,  not  in  the 
expectation  of  claiming  new  and  original  ideas,  but  to  secure  your 
attention  to  a  point  that  I  consider  of  great  importance  for  the 
development  of  an  important  branch  of  the  chemical  industries. 

"We  are  surrounded  by  an  immeasurable  quantity  of  nitrogen 
gas  in  the  atmospheric  air.  The  weight  of  the  atmosphere  surround- 
ing our  earth  is  calculated  to  be  10  trillions  of  pounds,  of  which 
7.77  trillion  pounds  is  nitrogen;  but,  in  spite  of  this  inexhaustible 
source  of  nitrogen,  we  are  not  able,  in  a  direct  way,  to  use  a  single 
pound  for  the  production  of  ammonia.  It  has  long  been  the 
endeavor  of  the  technical  chemist  to  convert  the  nitrogen  of  the  air 
into  ammonia,  but  up  to  this  hour  none  has  succeeded  in  doing 
it  with  practical  results.  We  are  still  compelled  to  use  as  sources 
for  the  production  of  ammonia  the  products  of  plant  or  animal  life. 

"The  nitrogen  of  the  air  must  pass  through  the  channels  of 
plant  life  to  reach,  in  the  products  of  the  animal  body,  their  highest 
degree  of  concentration.  Hoofs  and  horns,  with  15  to  16  per  cent. ; 
dried  blood,  with  19  per  cent.;  hair  and  wool  waste,  with  10  per 
cent.;  and  bones,  with  5  per  cent,  of  ammonia,  are  the  richest 
sources. 

"But  the  products  of  animal  life,  however,  even  if  they  were 
not  too  valuable  otherwise,  are  by  no  means  sufficient  to  satisfy  the 
wants  of  the  present  day  for  the  products  of  ammonia.  But  nature 
has  provided  an  inexhaustible  source  for  hundreds  of  years  to  come, 
in  the  residuum  of  plant  life  of  former  periods.  In  the  bituminous 


TREATISE  ON  COKE 


257 


coal  fields  and  in  the  deposits  of  brown  coal  are  lying  stored  up 
billions  of  pounds  of  nitrogen  waiting  to  be  converted  into  ammonia. 

"The  process  of  gaining  this  ammonia  is  incidental  to  the  pro- 
duction of  illuminating  gas,  to  the  production  of  coke,  and  to  the 
production  of  animal  charcoal.  In  distilling  the  bituminous  coal 
we  obtain  of  the  weight  of  coal  used,  4  to  6  per  cent,  of  tar  and 
6  to  10  per  cent,  of  ammoniacal  water  of  1.8°  B. 

"As  Professor  Lunge  has  shown,  the  nitrogen  contained  in  the 
coal  does  not  yield  the  amount  of  ammonia  that  we  might  expect: 


Possible  Yield 

Yield  of 

Possible  Yield 

of  Ammonia  Water 

Name  of  Coal 

Nitrogen 
Per  Cent. 

of  Ammonia 
Per  Cent. 

1.020  Specific  Gravity 
Per  Ton  of  Coal 

Gallons 

Wales  

.71 

1.10 

142 

Lancashire  

1.25 

1.52 

196 

Newcastle  

1.32 

1.60 

206 

Scotland 

1   44 

1  75 

226 

"  But  instead  of  these  figures,  the  practical  yield  per  ton  of  coal 
at  the  best  is  only  45  gallons  of  gas  water  of  1.020  specific  gravity, 
generally  only  25  gallons,  and  in  some  instances,  as  low  as  13  gallons. 

"The  ammoniacal  liquors  from  distillation  of  animal  refuse  are 
much  richer,  but  the  small  quantity  produced  allows  us  to  ignore 
the  same  as  a  very  insignificant  factor  in  the  production  of  ammonia 
salts.  The  consumption  of  ammonia  in  its  various  forms  has  grown 
enormously  in  the  last  20  years,  and  the  manufacture  of  illumina- 
ting gas  is  no  longer  sufficient  to  supply  the  increasing  demand  for 
ammoniacal  liquors.  On  the  other  hand,  the  inroad  that  electrical 
plants  for  illumination  have  been  making  yearly  on  the  production 
of  illuminating  gas  has  already  been  felt,  and  will  be  more  so  from 
year  to  year.  The  production  of  water  gas  and  oil  gas  are  other 
factors  that  are  cutting  down  the  amount  of  ammoniacal  waters 
produced. 

"But  there  is  another  source  for  tar  and  ammonia,  which,  so  far 
as  my  knowledge  goes,  has,  with  a  single  exception,  not  been 
worked  in  our  country. 

"  Rich  as  are  our  resources,  we  are  not  rich  enough  to  waste  con- 
tinually. It  seems  strange,  and  nevertheless  it  is  a  fact,  with  all 
the  ingenuity  of  the  American  people  in  the  advancement  of  the 
purely  mechanical  part  of  the  technical  industries,  we  have  been 
and  are  yet  slow  in  the  development  of  the  chemical  industries. 

"The  acid  manufacturer  of  Europe,  especially  of  England  and 
Germany,  had  commenced,  in  the  beginning  of  this  century,  to 
make  himself  independent  of  the  sulphur  mines  of  Sicily  by  using 
the  sulphurous  ores  of  his  immediate  neighborhood  and  to  utilize 
the  pyrites  for  making  his  sulphuric  acid.  It  has  been  only  within ' 


258  TREATISE  ON  COKE 

the  last  20  years  that  our  people  commenced  to  use  the  ores  that 
had  been  lying  under  their  feet,  and  today  even,  the  United  States 
consumes  more  sulphur  for  the  manufacture  of  sulphuric  acid  than 
any  other  nation. 

"It  is  the  same  with  productions  of  tar  and  ammonia  as  a 
by-product  of  the  manufacture  of  coke.  If  you  will  visit  our  coal 
region  today,  you  will  find  the  nightly  sky  illuminated  from  the 
fires  of  the  coke  ovens,  and  every  one  of  the  brilliant  fires  bears 
testimony  that  we  are  wasting  the  richness  of  our  land  in  order  to 
pay  the  wiser  European  coke  manufacturer,  who  saves  his  ammonia 
and  sends  it  to  us  in  the  form  of  sulphate  of  ammonia;  and  who 
also  saves  his  tar,  which,  after  passing  through  the  complex  proc- 
esses of  modern  organic  chemistry,  reaches  our  shores  in  the  form 
of  aniline  dyes,  saccharin,  nitrobenzol,  etc. 

"As  far  back  as  1768,  tar  had  been  produced  as  a  by-product  of 
the  coke  industry  by  a  chemical  process  at  Fishbach,  in  the  coal 
district  of  Saarbriicken  on  the  Rhineland.  The  general  opinion  of 
the  consumer  there  was  then,  and  most  likely  will  be  here  at  the 
present  time,  that  the  coke  produced  will  be  of  inferior  quality. 
Against  this  opinion  of  the  practical  coke  men,  it  has  always  been 
held  by  technical  chemists,  that  the  process  can  be  so  conducted 
as  to  yield  all  the  by-products  and  still  make  a  first-class  coke. 

"Since  about  1850,  the  producers  of  coke  in  France,  Belgium, 
England,  and  Germany  commenced  simultaneously  the  saving  of 
the  by-products. 

"At  St.  Etienne,  in  France,  a  system  of  furnaces  was  at  work  in 
1862  for  which  great  success  was  claimed  at  that  time.  The  gas 
and  other  volatile  products  of  the  coke  oven  were  conducted  to 
an  air  condenser,  in  which  the  tar  and  ammonia  were  condensed; 
the  non-condensable  gases  were  returned  to  the  furnace  as  fuel. 

"Scrubbers  and  condensers  have  been  improved  to  insure  com- 
plete condensation. 

"The  following  average  results  have  been  claimed: 

PER  CENT. 

Coarse  coke .    70 . 00 

Small  coke 1 .  50 

Waste  coke 2 . 50 

Graphite 50 

Tars 4.00 

Ammonia  water 9 . 00 

Gas 10.58 

Loss 1.92 

"The  net  gain  after  deducting  all  expenses  and  without  reckon- 
ing in  the  coke  was,  per  oven,  in  Besseges,  which  has  eighty-five 
ovens  in  operation,  111,446  francs.  For  eighty-five  ovens  this 
saving  amounts  to  94,990  francs  or  about  $18,938. 

"I  give  you  in  the  table  on  page  259  the  results  reported 
from  two  establishments  in  France. 


TREATISE  ON  COKE 


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PQH       PH 

"  I  will  not  endeavor  to  cover 
the  development  of  the  coke 
industries  of  Europe  for  the 
whole  period  since  1850.  I  have 
had  occasion  to  familiarize  my- 
self with  all  the  conditions  of 
this  industry,  and  am  in  posses- 
sion of  figures  and  plans  of 
Doctor  Otto's  successful  ovens, 
a  view  of  which  I  show  you. 
(See  Figs.  9  and  10.) 

"  In  1883,  a  system  of  twenty 
ovens  was  built  at  the  coke 
works  of  Gottesburg,  Silesia,  the 
results  from  which  were  so 
encouraging  that  in  the  follow- 
ing year  120  ovens  were  built. 

"  I  will  give  you  a  report  from 
a  manufacturer,  who,  two  sum- 
mers ago,  visited  the  Dahlhausen 
works  of  Doctor  Otto,  at  the 
mines  of  Millensiven  near  Dort- 
mund. Here  there  are  two  sets 
of  thirty  ovens  each,  which  are 
charged  alternately  every  other 
day.  The  gases  are  conducted 
by  large  iron  pipes  to  a  large 
basin,  where  a  part  of  the  tar 
will  be  condensed.  From  there 
it  is  led  to  the  coolers,  where 
the  remaining  tar  and  ammo- 
niacal  products  are  absorbed, 
and  the  gas,  purified,  is  returned 
to  a  gas  holder,  and  from  there 
is  redistributed  to  the  coke 
ovens,  to  the  boiler  fires,  and 
utilized  as  illuminating  gas 
throughout  the  works.  The  gas 
returning  to  the  coke  ovens  is 
mixed  with  hot  air  and  enters 
the  flues  of  the  bottom  and 
sides.  The  coke  produced  is 
an  excellent  product  and  finds 
a  ready  market  everywhere. 
It  has  not  the  silver  gray  or 
steel  color  of  our  Connellsville 
coke,  but  it  is  quite  as  good  in 
quality  as  ours." 


260  TREATISE  ON  COKE 

Festner-Hoffman  Coke  Oven. — The  general  design  of  the  Fest- 
ner-Hoffman  coke  oven  is  to  simplify  construction  and  operation 
in  the  manufacture  of  coke  and  saving  of  by-products.  The  recu- 
perative compartments  of  this  oven  are  somewhat  simpler  than  the 
double  regenerators  of  the  Otto  oven. 

In  the  treatment  of  dry  coals,  it  is  evident  that  a  high  heat 
with  quick  application  is  required  in  coking  such  coals;  it  is  also 
manifest  that  an  efficient  method  of  heating  the  air,  for  mixture 
with  the  returned  gas,  is  absolutely  necessary.  But  the  recuper- 
ators and  regenerators  should  be  designed  in  as  simple  and 
inexpensive  a  manner  as  possible,  consistent  with  efficiency  in  per- 
forming this  part  of  the  work  in  coking.  The  Festner  oven  has 
the  advantage  of  direct  and  continuous  work,  removing  the  neces- 
sity of  reversing  the  air  and  gas  currents,  as  in  the  Otto  oven, 
thus  avoiding  the  risk  of  explosions. 

The  most  important  improvement  appears  in  the  horizontal 
posture  of  the  side  flues  in  this  oven.  In  practical  operations,  it 
has  been  made  very  plain  that  the  oven  heat  from  the  combustion 
of  the  returned  gas  can  be  regulated  much  more  readily  in  ovens 
having  horizontal  flues  than  in  those  using  the  vertical  posture. 
The  danger  in  the  latter  arises  from  the  tendency  to  the  concen- 
tration of  excessive  heat  at  certain  localities  in  the  oven  flues, 
destroying  the  firebrick  conduits  and  lining. 

From  the  study  of  this  oven,  it  is  evident  that  in  its  design 
some  progress  has  been  made  in  the  right  direction  in  reducing  its 
cost  of  construction  and  expense  of  operation.  It  is  further  mani- 
fest that  additional  study  along  these  lines  would  be  helpful  in  the 
introduction  of  these  retort  coke  ovens  in  the  United  States. 

Mr.  E.  Festner,  Director,  Silesia  Coal  and  Coke  Works,  in  a 
paper  read  before  the  German  Mining  Engineers,  September  5,  1892, 
describes  this  oven,  shown  in  Fig.  18,  as  follows: 

"The  well-known  Otto-Hoffman  oven  is  called  the  regenerative 
oven;  in  distinction  to  this  I  will  call  my  Festner-Hoffman  oven 
the  recuperative  oven  (referring  to  the  similarly  constructed  Pon- 
sard  gas  furnace),  the  purpose  of  which  is  to  dispense  with  the 
continual  reversing  of  the  regenerative  ovens  and  to  effect  a  per- 
manent heating  of  the  air  necessary  for  combustion.  In  this  work 
I  was  assisted  by  Coke  Inspector  Hoffman,  a  very  able  engineer 
and  the  father  of  the  Otto-Hoffman  ovens. 

"  During  long  experience  with  the  coking  process,  I  have  always 
found  the  horizontal  flues  and  the  somewhat  strong  side-walled 
ovens  better  than  the  Coppee  ovens  with  vertical  flues.  The  former 
can  be  worked  at  a  higher  heat  and  can  be  examined  more  readily, 
particularly  in  the  flues;  therefore,  I  equipped  my  ovens  last  year 
with  horizontal  drafts  similar  to  the  Simon-Carves  system,  which 
is  used  to  great  advantage  at  Bulmke,  near  Gelsenkirchen. 

"In  building  this  new  plant  I  arranged  my  appliances  for  the 
saving  of  by-products,  as  their  advantages  are  evident.  As  the 


261 


262  TREATISE  ON  COKE 

quality  of  the  dry  coal  used  required  a  very  high  heat,  it  became 
necessary  to  heat  the  air  for  combustion  as  high  as  possible,  and 
as  grave  defects  appeared  in  the  reversing  process,  the  recuperative 
oven  was  suggested  more  from  necessity  than  inclination. 

"In  explanation  I  will  say  that  I  call  the  chamber  where  the 
coal  is  placed  for  coking  and  the  side  of  oven  where  the  coke  pusher 
operates,  the  front  side;  and  the  other,  where  the  coke  is  discharged 
and  cooled,  the  rear  side.  The  chamber  of  this  oven  is  29^  feet 
long,  23  inches  wide,  and  5  feet  11  inches  high.  The  oven  contains, 
when  full,  6^  tons  of  washed  coal  for  a  48-hour  charge.  The 
chamber  walls  are  6  inches  thick,  and  the  flue  walls  about  the 
same  thickness. 

"  The  ovens  are  combined  in  groups  of  thirty  each.  The  hot-air 
flues,  lying  underground,  consist  of  two  systems  for  a  battery  of 
thirty  ovens. 

"The  coking  chamber  is  filled  with  coal  through  the  three  char- 
ging ports  a.  The  gas  is  conveyed  through  the  flues  b  into  the 
condensing  apparatus.  The  exhausted  gases  return  through  the 
pipes  c  and  d  and  are  sent  by  the  hot-air  current  that  enters  at  e,  ev 
e2,  through  the  dividing  pipes  /,  /lf  on  the  front,  and  /2  on  the 
back.  The  gases  are  first  led  forwards  and  back  in  the  hot  flues 
g  and  glt  under  the  oven  bottom;  they  then  rise  in  the  vertical  hot 
flue  h  on  the  rear  side,  passing  through  the  horizontal  flue  i  to  the 
front  side;  they  then  go  backwards  in  /,  and  forwards  again  in  ;\, 
falling  through  k  to  the  lowest  horizontal  hot  flue  /  in  order  to 
reach  the  central  flue  m,  which  leads  the  gas  under  the  boilers. 
After  the  heating  they  receive  in  passing  through  these  two  levels, 
the  gases  are  led  through  n,o,  and  mv 

"The  air  to  be  heated  enters  from  the  outside  at  p,  falls  to  the 
horizontal  air  canal  q,  through  the  flue  system  r,  r^  r2,  r3,  r4,  r5, 
and  re,  as  seen  in  drawing,  and  is  easily  warmed  in  this  system 
by  means  of  the  hot  flue  /.  From  here  the  air  is  led  through  the 
horizontal  air  flue  5  to  the  vertical  flues  t  in  order  to  get  to  the 
main  system  u,  uv  M2,  and  also  to  v,  vv  v2,  v3,  from  whence  it  is  led 
as  hot  air  through  the  vertical  drafts  e,  e'lt  and  e2,  to  be  used  in  the 
combustion.  The  heating  that  the  air  in  the  flue  system  under- 
goes, through  continually  impinging  against  the  small  piles  w,  etc., 
is  excellent  and  the  heat  of  combustion  rises  to  1,650°  F.  In  the 
latter-described  arrangement  is  the  characteristic  of  our  oven,  for 
which  Hoffman  and  I  have  applied  for  a  patent. 

"According  to  the  results  in  question,  from  this  new  oven  in 
Gottesburg,  nothing  remains  to  be  desired;  they  can  be  heated 
very  high,  are  easily  regulated,  and  are,  according  to  experi- 
ments that  I  made  with  similar  ones  built  by  me  in  Hermsdorf, 
almost  indestructible,  so  that  these  new  ovens  can  be  recommended 
as  the  best. 

"The  waste  gas  from  flue  m  supplies  five  boilers  of  45  horse- 
power. With  this  heat,  the  boilers  not  only  supply  the  necessary 


TREATISE  ON  COKE  263 

steam  for  the  condensing  apparatus,  but  power  for  electric  lighting 
of  the  whole  works,  as  well  as  for  running  various  small  machines. 

"In  order  to  have  as  small  a  depression  as  possible  in  the  hot 
flue,  a  ventilator  plant  is  necessary,  which,  as  in  the  Otto-Hoffman 
oven,  helps  to  regulate  the  supply  of  air  and  leads  to  a  uniform 
heating  of  the  hot  flue.  The  slight  depression  in  the  hot  flue 
stops  the  gas  in  the  chamber  from  passing  through  the  cracks 
in  the  walls  directly  into  the  hot  flue  and  thereby  being  lost  to 
condensation. 

"The  cost  of  the  oven  proper,  from  the  excavation  to  the  time 
of  firing  the  oven,  is  estimated,  in  Germany,  at  $935.  The  cost  of 
oven  and  by-product  apparatus  would  therefore  be  as  follows,  in 
Germany : 

Oven ' $935 . 00 

By-product  apparatus 1,600.00 


Total $2,535.00 

"In  the  United  States,  the  cost  would  be  somewhat  more, 
approaching  about  $3,000  per  oven." 

No  record  is  given  of  the  work  of  this  oven,  but  it  is  fair  to 
estimate  its  coke  and  by-products  about  the  same  as  the  Otto- 
Hoffman  oven,  a  charge  of  6.889  net  tons  of  dry  coal  every  48 
hours  giving  5.166  net  tons  of  coke  every  2  days,  or  2.583  net 
tons  daily. 

The  coal  used  is  given  as  an  average  of  its  quality  in  the  dis- 
trict referred  to  in  the  foregoing  article  as  follows: 

PER  CENT. 

Moisture .      .74 

Carbon 84.29 

Hydrogen 4.61 

Nitrogen 1 . 62 

Oxygen 4.77 

Ash..  3.97 


Total 100.00 

Semet-Solvay  Coke  Oven. — The  Semet-Solvay  retort  coke  oven, 
Fig.  19,  came  into  appreciative  notice  in  Europe,  in  1887.  This 
oven  was  evidently  designed  to  secure  three  chief  elements  in  the 
coking  of  coal  and  saving  its  by-products. 

1.  To  coke  dry  coals,  such  as  inherit  only  15  to  17  per  cent, 
of  volatile  combustible  matter ;  this  is  secured  by  the  quickly  applied 
heat  during  the  initial  operation  of  coking,  thus  obtaining  the  full 
benefit  of  the  fusing  matters  in  the  coal  and  producing  the  hardest- 
bodied  coke  possible  with  such  quality  of  coal. 

2.  To  store  heat  in  the  oven  walls,  to  be  made  available  in 
starting  the  coke  operation  after  a  fresh  charge  of  coal  has  been 
placed  in  the  oven,  avoiding  the  expensive  auxiliary  arrangements 
of  regenerators  or  recuperators. 


264  TREATISE  ON  COKE 

3.  To  secure  in  a  direct  and  simple  manner  the  by-products 
of  tar  and  ammonia  in  coking,  enhancing  the  profit  of  the  coke 
manufacturer. 

An  examination  of  the  accompanying  plans  -and  sections  of 
this  coke  oven  will  show  the  general  scope  of  its  design.  The 
oven  chamber  is  usually  30  feet  long,  1  foot  4^  inches  wide,  and 
5  feet  6  inches  high.  These  dimensions  may  be  increased  or 
diminished  to  meet  the  requirements  of  coking  each  quality  of 
coal.  Its  side  walls  are  faced  with  flued  and  jointed  tiles  in  hori- 
zontal posture,  which  affords  the  best  condition  for  the  regulation 
of  the  heat  and  its  proper  distribution,  so  as  to  avoid  its  destruc- 
tive concentration  at  any  part  of  the  oven. 

These  flued  tiles  are  quite  thin,  quickly  transmitting  the  heat 
from  the  combustion  of  the  returned  gases  to  the  charge  of  coal. 
This  heat  is  sustained  by  drawing  on  the  heat  stored  between  the 
flued  lining  of  the  ovens  in  the  dividing  walls.  This  stored  heat 
is  maintained  by  the  return  of  the  surplus  heat  toward  the  close 
of  the  coking  of  each  charge,  and  is  ready  to  be  used  in  supple- 
menting the  heat  of  ovens  on  the  introduction  of  each  fresh  charge 
of  coal,  avoiding  the  chilling  of  the  fusing  matter  in  the  coal  by  a 
slow  process  of  coking. 

In  this  oven,  the  massive  arch  and  covering  A  afford  a  very 
important  second  heat-storage  reservoir  for  each  oven,  which 
insures  the  maximum  heat  at  the  upper  portion  of  the  charge  of 
coking  coal.  These  two  repositories  for  heat  storage,  the  walls  and 
the  arch,  obviate  the  necessity  of  auxiliary  appliances  for  heating 
the  air  for  combustion  of  the  gases,  which  are  essential  in  other 
systems. 

The  oven  is  capable  of  coking  the  richer  or  pitchy  coals,  but 
its  chief  merit  consists  in  its  successful  treatment  of  coals  low  in 
hydrogenous  matters,  which  are  difficult  to  coke  in  ordinary 
ovens.  It,  therefore,  measurably  anticipates  a  time  when  the 
chief  sources  of  the  best  coking  coals  shall  have  been  reduced 
in  extent,  and  when  the  coke  manufacturer  will  be  compelled 
to  fall  back  on  the  less  valuable  or  dry  coking  coals  to  maintain 
the  coke  supply. 

The  design  for  an  oven  to  coke  the  rich  or  pitchy  coals  will,  in 
time,  engage  the  attention  of  oven  builders,  reversing  the  heat 
conditions  of  the  Semet-Solvay  oven,  to  produce  coke  without  the 
usual  inflated  cellular  structure  now  barring  the  use  of  such  coals 
for  the  manufacture  of  metallurgical  coke. 

It  may  be  noted  that  the  Semet-Solvay  ovens  afford  sufficient 
surplus  heat  to  make  steam  in  boilers,  located  near  the  ovens,  for 
all  purposes  of  all  the  operations  of  the  manufacture  of  coke  and 
saving  of  the  by-products. 

Mr.  E.  Festner,  director  of  the  Selician  Coal  Works,  Gottesburg, 
reports  that  a  Semet-Solvay  oven  will  coke  1,440  tons  of  coal, 
producing  1,125  tons  of  coke  per  year.  About  78  per  cent,  of  coke 


TUTT 


Covering  of  Red  Bricks  on  Edge 

To  be  laic/ offer  fne  Masonry  nas  ae-Hled 


Section 
AA 


Section 
3-B 


Sect/on 
OC 


fire  Brick 


[01 


P 


fire  Brie  ft 


U LL 


fire  Brick 


Red BricK 


ft) 


17303— vi 


FIG.  19.     DETAILS  OF  BRICKWORK  FOR  C 


^        Arch  e>/ 
Red  Bricks 

Arch  of 
Refractory  Bricks 


_LL 


P/an 


Gas 


E 


TTt 


t1ea+  f/ues 


--^G#& 


OVENS.     THE  SOLVAY  PROCESS  COMPANY 


TREATISE  ON  COKE  265 

is  obtained  from  the  coal  charged;  all  24-hour  coke.     He  further 
gives  the  cost  of  this  oven  and  its  appliances,  in  Europe,  as  follows: 

Cost  of  oven  complete $1,168.75 

Apparatus  for  saving  by-products 1,402.50 

Boiler  plant,  heated  with  gas 490  87 

Storage  bin  and  coal  mixer 420  75 


Total  cost  per  oven $3,482  87 

In  the  United  States,  the  cost,  per  oven,  of  such  a  plant  would 
exceed  the  above. 

It  has  been  suggested  that  the  use  of  silica  material  in  the 
flued  tiles  in  the  oven  lining  would  add  to  their  permanence  in 
performing  their  important  functions  in  the  oven  and  reduce 
expenses  of  repairs. 

A  plant  of  twelve  Semet-Solvay  retort  coke  ovens  is  now  in 
operation  at  the  works  of  the  Solvay  Process  Company,  near 
Syracuse,  New  York.  This  plant  has  been  constructed  in  a  very 
perfect  and  substantial  manner  with  improved  appliances  for 
extracting  and  saving  the  by-products  of  tar  and  ammonia.  It  is 
designed  at  some  future  time  to  add  twelve  more  ovens  to  the 
present  plant,  making  in  all  twenty-four  ovens.  The  exhauster 
and  apparatus  for  securing  the  by-products  are  sufficiently  large 
to  take  care  of  the  products  of  twenty -four  ovens  or  more.  The 
main  design  is  to  obtain  coke  as  free  as  possible  from  sulphur, 
and  at  the  same  time  secure  the  by-products  of  tar  and  ammonia. 

The  plan  of  this  oven  is  shown  in  Fig.  19,  which  has  been 
kindly  furnished  by  W.  B.  Coggswell,  Esq.,  general  manager  of 
the  Solvay  Process  Company,  of  Syracuse.  The  cost  of  this  plant 
is  as  follows : 

Ammonia  concentrator $   1,584. 74 

Boilers .  10,210.56 

Coal  trestle 3,039.  58 

Coal- house  plant 5,027 . 23 

Chimneys 3,107.93 

Pusher 3,112.46 

Producer 701 . 00 

Ovens  (12) 28,685.30 

By-product  building 7,365.  74 

Washers  (2) 2,856 . 69 

Exhausters  (2) 2,51 1.16 

Shafting 841 . 47 

Hydraulic  mains  (2) 2,281 . 84 

Gas  condensers  (4) 6,521   42 

Piping  and  other  contingencies 10U67.32 


Total $88,014.44 

From  this  it  will  be  seen  that  the  ovens  cost  $2,390.45  each; 
the  ovens  with  the  appliances  and  pusher  will  cost  $7,334.53  each. 
Increasing  this  plant  to  twenty-four  ovens,  and  estimating  the 
cost  of  the  twelve  additional  ovens  at  $2,000  each,  the  aggregate 


266      -  TREATISE  ON  COKE 

cost  of  the  plant  will  be  $112,014.44.  The  average  cost  of  the 
ovens  is  $2,195.23  each.  The  average  cost  of  the  by-product-saving 
apparatus  is  $2,472.04  for  each  oven.  It  is  quite  probable  that 
with  a  still  further  increase  of  ovens  the  average  cost  of  ovens  and 
by-product  appliances  would  be  much  reduced. 

The  coal  used  in  these  ovens  is  small  or  fine  coal  procured 
from  the  Morris  Run  Coal  Company,  Tioga  County,  Pennsylvania. 
It  is  constituted  as  follows : 

PER  CENT. 

Moisture '        1600 

Volatile  matter 19. 1200 

Fixed  carbon ,- 70 . 7800 

Ash 8.9100 

Sulphur 7318 

The  theoretic  coke  in  the  above  coal  is  80.12  per  cent. 

During  the  month  of  June,  1895,  1,656^  net  tons  of  coal  was 
used  in  the  twelve  coke  ovens,  producing  1,273J  net  tons  of  large 
coke  and  46£  tons  of  breeze,  exhibiting  a  total  product  of  1,320  tons 
of  coke  and  breeze.  The  total  product  of  coke  is  79.68J  per  cent, 
of  the  coal  charged  into  ovens;  of  this  2.80  per  cent,  is  breeze,  or 
small  coke,  leaving  of  marketable  coke  76. 87^  per  cent.  As  the 
theoretic  coke  from  this  coal  is  80.12  per  cent.,  it  is  evident  that 
very  little  waste  of  fixed  carbon  has  been  made  in  coking.  On  the 
other  side  it  appears  that  very  little  carbon  has  been  deposited 
from  the  volatile  hydrocarbons  in  coking;  this  is  further  confirmed 
by  the  absence  of  the  bright  silver  glaze  that  evidences  this  deposit 
on  coke. 

The  daily  charge  for  each  oven  is  4.6  net  tons  of  coal.  The  coke 
and  breeze  produced  are  3.67  net  tons.  One  oven  produces  106.12 
net  tons  of  marketable  coke  per  month  or  1 ,273.44  net  tons  per  year. 

The  by-products  of  tar  and  sulphate  of  ammonia  made  during 
the  month  of  June,  are  as  follows: 

PER  TON  OF  COAL 

Tar 43. 6    pounds 

Sulphate  of  ammonia 9 . 88  pounds 

The  revised  cost  of  labor  in  making  coke  and  saving  by-products 
is  given  at  $1.08  per  net  ton.  It  is  estimated  that  with  a  twenty- 
four  oven  plant  this  cost  would  not  greatly  exceed  60  cents  per 
net  ton  of  coke  made  and  by-products  saved.  These  ovens  are 
run  continuously  with  three  shifts  of  men,  making  the  cost  of  the 
work  somewhat  above  other  types  of  ovens.  The  value  of  the 
by-products,  per  ton  of  coke  made,  is  placed  at  48  cents. 

With  the  dry  quality  of  coking  coal  used  in  these  ovens,  inherit- 
ing only  17  to  19  per  cent,  of  volatile  combustible  matter,  it  is 
evident  that  the  results  of  the  retort  coke  ovens  clearly  indicate 
that  this  is  the  best  oven  for  coking  this  rather  inferior  coal.  The 
percentage  of  coke  made,  76.875,  with  its  hardness  of  body  and  its 


TREATISE  ON  COKE  267 

consequent  condition  to  resist  dissolution  in  its  passage  down  a 
blast  furnace-  by  the  action  of  the  ascending  gases,  gives  it  additional 
commendation  in  producing  metallurgical  coke. 

A  similar  quality  of  coal  coked  in  the  beehive  oven  afforded 
only  61  per  cent,  of  coke  rather  softer  in  body  than  the  retort  coke, 
and  consequently  less  valuable  as  a  fuel  in  metallurgical  operations. 

When  the  several  types  of  coke  ovens  shall  have  been  considered, 
with  cost  of  plant,  expenses  of  operating,  and  physical  properties 
of  their  products  of  coke  compared,  a  general  review  of  the  merits 
and  demerits  of  each  kind  of  oven  will  be  submitted.  At  this  time 
it  can  only  be  pointed  out  that  such  an  analysis  of  coking  will 
embrace  two  lines  of  determinations:  (1)  Whether  metallurgical 
coke  is  the  prime  requirement,  with  or  without  by-products  as  a 
secondary  matter;  (2)  when  the  by-products  are  the  chief  product, 
with  coke  only  a  secondary  interest. 

With  the  largely  increased  cost  of  a  coking  plant  for  saving 
by-products,  and  its  increased  cost  in  labor  above  the  coke  plants 
without  the  saving  of  by-products,  it  becomes  a  serious  consider- 
ation whether  the  market  value  of  the  by-products  will  secure 
increased  profits  to  cover  increased  investment  in  plant  and  extra 
labor  expenses  to  the  coke  manufacturer. 

In  a  communication,  July  10,  1894,  F.  R.  Hazard,  Esq.,  treas- 
urer of  the  Solvay  Process  Company,  of  Syracuse,  New  York, 
states : 

"In  the  matter  of  the  present  results  of  the  block  of  Semet- 
Solvay  ovens,  in  Syracuse,  we  would  say  that,  running  on  Morris 
Run  coal,  the  percentage  of  marketable  coke  to  coal  used  was 
78.2  per  cent.  In  addition  to  the  coke  there  is  from  2  to  3  per  cent, 
of  breeze.  The  by-products  amount  to  42J  pounds  of  tar  per  ton 
of  coke,  and  16.12  pounds  of  sulphate  of  ammonia  per  net  ton  of 
coke.  We  will  be  obliged  if  you  will  make  this  correction  in  the 
revision  of  your  articles. 

"We  cannot  use  our  small  block  of  twelve  ovens  for  a  fair 
criterion  of  either  original  or  operating  cost.  By  the  European 
practice,  the  cost  of  a  Semet-Solvay  oven  is  $1,000  against  $1,200 
for  an  Otto-Hoffman  oven;  and  the  Semet-Solvay  oven  will  pro- 
duce double  the  quantity  of  coke,  requiring  but  22  hours  against 
48  hours  for  the  Otto-Hoffman  oven.  The  cost  is  for  the  oven 
only,  not  the  by-products.  The  cost  of  operating  a  block  of  twenty- 
five  Semet-Solvay  ovens,  making  twenty-eight  charges  of  4±  net 
tons  each  in  24  hours,  equal  to  126  net  tons  of  coal  producing 
101.5  net  tons  of  coke,  is  two  engineers  and  twenty  laborers.  At 
$2.25  per  day  per  engineer,  and  $1.40  per  day  for  laborers,  this 
would  amount  to  $32.50,  operating  cost  for  101.5  net  tons  of  coke, 
or  32  cents  per  net  ton  of  coke.  One  extra  man  will  attend  to  the 
by-product  works." 

For  the  large  class  of  dry  coals,  this  oven  is  admirably  adapted  to 
produce  very  good  metallurgical  coke,  as  good  as  can  be  made  from 


268  TREATISE  ON  COKE 

this  dry  coking  coal.  It  may  be  submitted  here,  as  a  general  princi- 
ple, that  first-class  coke  cannot  be  made  from  second-class  coals. 
Twelve  Semet-Solvay  coke  ovens  with  apparatus  for  saving  the 
by-products  of  tar  and  ammonia  sulphate  have  been  in  operation 
during  the  year  1894  at  the  large  chemical  works  of  the  Solvay 
Process  Company,  Syracuse,  New  York.  Mr.  W.  B.  Coggswell, 
the  managing  director,  has  kindly  furnished  the  statement  on  this 
and  the  following  page  of  the  year's  product  of  coke,  breeze,  and 
by-products.  The  large  output  of  coke  is  remarkable,  as  it  greatly 
exceeds  the  best  record  of  retort  ovens  that  has  come  to  our  notice. 
From  the  strikes  at  the  coal  mines  during  the  year,  the  output  of 
coke  was  reduced  owing  to  the  insufficient  supply  of  coal. 

Experiments  in  these  ovens  with  Connellsville  coal,  for  the 
Illinois  Steel  Company,  afforded  remarkable  results  in  the  increased 
product  of  coke.  It  was  shown  that  coke  could  be  made  from  this 
coal  in  16  hours  that  in  quality  was  satisfactory  to  the  represent- 
ative of  this  company,  Mr  Whiting,  who  remained  at  ovens  during 
the  time  of  the  experiments.  This  indicates  a  daily  output  of 
coke  of  nearly  6  tons.  During  two  visits  of  the  writer  to  these 
works,  very  full  statements  of  the  work  of  the  ovens  were  kindly 
furnished. 

COKE-OVEN  STATEMENT  SOLVAY  PROCESS  COMPANY 
FOR  1894 

Coal  used,  total  short  tons,  2,000  pounds 21,825.60 

Coal  used  per  oven,  short  tons 1,818. 80 

Coke  produced,  total  short  tons 17,531  20 

Coke  produced  per  oven,  short  tons 1,460. 90 

Breeze  produced,  total  short  tons 678. 10 

Breeze  produced  per  oven,  short  tons 56. 50 

Percentage  of  large  coke  to  coal 80 . 33 

Percentage  of  breeze 3. 17 

Percentage  total  coke  to  coal 83 . 50 

Ammonia  sulphate,  total  pounds 309,385.00 

Ammonia  sulphate  per  oven,  pounds 25,782.00 

Ammonia  sulphate  per  ton  of  coal,  pounds 14 . 27 

Tar  produced,  total  pounds 917,230.00 

Tar  produced  per  oven,  pounds 76.435.00 

Tar  produced  per  ton  of  coal,  pounds 42.20 

Owing  to  insufficient  supply  during  the  strike,  the  production 
was  limited  by  the  receipts  of  coal. 


WEST  VIRGINIA  COALS  IN  SEMET-SOLVAY  OVENS 

The  following  figures  are  the  results  of  a  test  of  Davis,  and 
Thomas,  West  Virginia,  coals  made  in  Semet-Solvay  ovens  at 
Syracuse,  February  23  to  27,  1899.  Four  ovens  were  coked  for  the 
by-product  test.  Duration  of  coking  24  hours.  One  oven  was 
coked  20  hours,  and  another  22  hours,  and  in  both  cases  the  volatile 


TREATISE  ON  COKE 


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270 


TREATISE  ON  COKE 


matter  was  practically  all  driven  off.     The  following  are  the  figures 
as  to  yield  of  coke,  ammonia,  and  tar  from  the  Davis  coal: 


Pounds 

Per  Cent. 

Weight  of  coal  used  in  four  ovens  at  8,825  pounds  
Weight  of  coke  produced 

35,300 

27  400 

Coke  yielded 

77.62 

Moisture  in  coal  . 

4.21 

Moisture  in  coke  .  .  . 

2.89 

Breeze  produced  

1  270 

Breeze  equal  

3.60 

Moisture  in  breeze  

20.00 

Taking  into  consideration  the  moisture  in  the  coal  and  coke, 
the  figures  are  as  follows: 


Pounds 

Moisture 
Per  Cent. 

Coal 
Per  Cent. 

Weight  of  coal  charged  
Weight  of  dry  coal  
Weight  of  coke  produced  
Weight  of  dry  coke  

35,300 
33,814 
27,400 
26,609 

4.21 

2.89 

Yield  of  large  coke  

78.69 

Weight  of  breeze 

1  270 

20  00 

Weight  of  dry  breeze. 

1  016 

Yield  of  breeze  

3.00 

Total  yield  

81.69 

The  by-products  per  2,000  pounds  of  coal  are:     sulphate  of 
ammonia,  18.51  pounds;  tar,  41.14  pounds;  gas,  8,000  cubic  feet. 

ANALYSIS  OF  DAVIS  COAL  AND  COKE 


Coal 

Per  Cent. 

Coke 
Per  Cent. 

Volatile  matter 

23  720 

1    1200 

Fixed  carbon  .  .  . 

68  .  370 

88  6000 

Ash 

7  910 

10  2800 

Sulphur  .         .  .  .  .'  

.737 

.6890 

Phosphorus  

.0092 

The  following  is  the  test  of  Thomas  coal : 


Pounds 

Per  Cent. 

Weight  of  coal  used  in  three  ovens  at  9  945  pounds 

29  835 

Weight  of  coke  produced.  . 

22  760 

Coke  yielded.  .  .         .                              .         

76.28 

Moisture  in  coal  

3.00 

Moisture  in  coke  
Breeze  produced  

1,215 

2.00 

Breeze  equal  . 

4  07 

Moisture  in  breeze 

25.00 

TREATISE  ON  COKE 


271 


Taking  into  consideration  the  moisture  in  the  coal  and  coke, 
the  figures  are  as  follows: 


Pounds 

Moisture 
Per  Cent. 

Coal 
Per  Cent. 

Weight  of  coal  charged  

29  835 

3   00 

Weight  of  dry  coal  

28  940 

Weight  of  large  coal     

22  760 

2  07 

Weight  of  dry  coke 

22  ^0^ 

Yield  of  large  coke  

77   01 

Weight  of  breeze  
Weight  of  dry  breeze   

1,215 
912 

25  .  00 

Yield  of  breeze 

31  n 

Total  yield   . 

Qf)     1  1 

The  by-products  for  2,000   pounds  of  coal   are:     sulphate  of 
ammonia,  20.66  pounds;  tar,  47.96  pounds;  gas,  8,500  cubic  feet. 

ANALYSIS  OF  THOMAS  COAL  AND  COKE 


•         .•  ;'  ".-.                              -  •         '•    v~ 

Coal 
Per  Cent. 

Coke 
Per  Cent. 

Volatile  matter  

25  420 

1    200 

Fixed  carbon  

63  400 

85  450 

Ash  . 

U180 

i  ^  i^n 

Sulphur  

678 

663 

Phosphorus  

Crushing  strength 

COMPARISON  OF  SEMET-SOLVAY  TESTS 


Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Connellsville  coal 

29  02 

61    61 

9  37 

770 

Connellsville  coke  
Davis  coal  
Davis  coke.    . 

1.85 
23.72 
1   12 

87.07 
63.57 
88  60 

11.08 
7.91 
10  28 

750 
.737 

669 

.0180 

0092 

Thomas  coal.  . 

25  42 

63  40 

11   18 

672 

Thomas  coke  

1.20 

85.45 

13.35 

.665 

The  above  analysis  of  Connellsville  coal  is  fully  2  per  cent, 
below  the  average  of  usual  volatile  matter,  and  the  phosphorus  is 
also  higher  than  usual.  The  yield  of  large  coke  from  Connellsville 
coal  was  smaller  than  that  from  West  Virginia  coal,  due  to  the 
higher  percentage  of  volatile  matter.  The  tests  show  that  not 
only  none  of  the  fixed  carbon  is  lost  in  the  retort  type  of  ovens, 


272 


TREATISE  ON  COKE 


273 


but  that  there  is  an  increase  over  the  theoretical  yield;  this  is 
probably  deposited  by  the  escaping  gases.  The  same  results  are 
obtained  from  all  coals. 

Recent  Improvements  in  Semet-Solvay  Ovens. — The  following 
description  of  the  recent  improvements  in  the  Semet-Solvay  coke 
oven  has  been  furnished  by  the  general  manager  and  engineer  of 
the  Semet-Solvay  Company,  Mr.  W.  H.  Blauvelt: 

Fig.  19  exhibits  the  longitudinal  and  cross-sections  of  this  oven 
in  its  normal  condition  as  constructed  at  the  experimental  plant  at 
the  Solvay-Chemical  Works,  Syracuse,  New  York.  Since  its  instal- 
lation at  these  works  this  normal  type  has  been  mainly  followed  in 
the  construction  of  coking  plants  in  various  localities  in  the  United 


FIG.  21  (a).     VIEW  OF  REAR  END  OF  SEMET-SOLVAY  COKE  PLANT  AT 
DUNBAR,  PENNSYLVANIA 

States.  These  ovens  had  four  horizontal  lines  of  heating  flues.  The 
coking  chambers  were  30  feet  long,  16^  inches  wide,  and  5£  feet 
high,  affording  a  daily  output  of  marketable  coke  of  4.4  tons. 

Fig.  20  shows  the  longitudinal  and  cross-sections  of  the  enlarged 
and  improved  oven.  It  will  be  evident  that  an  additional  heating 
flue  has  been  added  to  the  height  of  this  overt,  giving  it  five  heating 
flues.  Its  length  has  been  increased  from  30  to  35  feet.  The  output 
of  marketable  coke  from  this  enlarged  oven  is  given  as  7  to  9  tons 
per  day.  The  largely  increased  capacity  of  this  oven  has  evidently 
been  secured  by  the  enlargement  of  its  length  and  height,  as  well 
as  from  the  compression  of  the  charge  of  coal  from  its  increased 
height.  The  width,  16^  inches,  remains  unchanged. 

Semet-Solvay  Plant  at  Dunbar,  Pennsylvania. — Fig.  21  shows 
three  views  of  the  Semet-Solvay  plant  of  fifty  by-product  ovens 
built  in  1895,  adjoining  the  plant  of  the  Dunbar  Furnace  Company. 


274 


TREATISE  ON  COKE 


The  coal  used  is  Connellsville  coal.  This  plant  was  one  of  the 
earliest  Semet-Solvay  plants  in  the  United  States  and  the  ovens 
are  built  of  the  early  type  illustrated  in  Fig.  19.  There  are  two 


w  OF  RAM  AND  FRONT  OF  OVENS 


symmetrical  batteries  of  twenty-five  ovens  each.  A  detailed 
description  of  these  ovens  will  be  found  in  Mines  and  Minerals, 
February,  1900,  page  297. 


FIG.  21  (c).    VIEW  SHOWING  ARRANGEMENT  OP  BY-PRODUCT  APPARATUS 

The  following  is  Mr.  Blauvelt's  letter  in  regard  to  the  present 
status  of  the  Semet-Solvay  oven : 


TREATISE  ON  COKE  275 

SYRACUSE,  N.  Y.,  June  19,  1903. 
MR.  JOHN  FULTON,  136  Park  Place,  Johnstown,  Pa. 

Dear  Sir: — Since  the  last  edition  of  your  book  was  published,  the 
growth  of  the  Semet-Solvay  oven  has  been  very  rapid  and  there  are  now 
in  this  country  nearly  1,100  civens,  either  in  operation  or  under  construc- 
tion. The  principal  advance  has  been  in  the  size  of  the  units,  that  is,  the 
size  of  the  ovens  and  the  number  of  ovens  in  a  block.  In  1895,  the  standard 
block  of  Semet-Solvay  ovens  was  twenty-five  ovens,  each  having  a  capacity 
of  4.4  tons  of  coal.  Now  the  ovens  are  built  forty  in  a  block,  with  a  capacity 
of  from  7  to  9  tons  each,  so  the  unit  has  risen  from  110  tons  of  coal  per  day 
to  360  tons  per  day.  The  increase  in  the  capacity  of  the  ovens  has  been 
obtained  mainly  by  increasing  the  height.  The  height  of  the  charge  was 
formerly  4  feet  UTS  inches;  now  the  standard  is  6  feet  2f  inches,  and  we 
have  successfully  operated  ovens  9  feet  high,  and  130  of  these  largest  ovens 
are  in  the  course  of  construction.  The  length  has  also  been  increased  from 
30  feet  to  35  feet.  It  was  thought  that  the  increased  height  might  have 
some  effect  on  the  physical  quality  of  the  coke,  making  it  more  dense  near 
the  bottom  of  the  oven,  but  it  has  not  been  found  to  be  the  case.  There 
is  no  visible  increase  in  density  in  the  coke  on  account  of  the  higher  ovens. 
We  have  not  found  it  desirable  to  change  the  width  of  oven  originally  adopted 
in  this  country,  namely  an  average  of  16£  inches.  This  width  permits 
almost  all  coals  to  be  coked  thoroughly  .in  from  22  to  24  hours,  and  all 
things  considered,  this  is  found  to  be  the  most  advantageous  coking  time. 
Wider  ovens  have  been  tried  up  to  20  inches,  but  the  output  of  coke  per 
day  has  proved  to  be  less  than  with  the  standard  width. 

Other  improvements  about  the  ovens  themselves  have  been  of  a  minor 
nature,  mainly  the  perfecting  of  details,  looking  to  more  economical  and 
efficient  construction.  Electricity  has  been  substituted  for  steam  on  the 
pushers  and  for  man  power  in  the  handling  of  the  charging  larries.  There 
has  been  no  opportunity  for  improvement  in  the  control  of  the  gas  in  the 
flues  or  the  regulation  of  the  heat  on  the  ovens,  as  these  essential  points 
have  always  been  thoroughly  under  control  and  entirely  satisfactory.  The 
introduction  of  our  inclined  coke  car,  which  permits  the  very  even  distribu- 
tion of  the  coke  as  it  is  pushed  from  the  oven,  over  a  large  surface,  thus 
permitting  prompt  and  efficient  quenching  with  a  minimum  of  moisture, 
has  entirely  overcome  one  of  the  former  handicaps  of  retort-oven  coke, 
namely,  the  high  moisture,  and  in  combination  with  our  system  of  quenching 
by  the  use  of  a  large  stream  of  water,  the  coke  may  be  kept  quite  as  dry 
as  in  the  best  beehive  practice.  By  the  use  of  this  coke  car  the  handling 
of  the  coke  is  reduced  to  an  absolute  minimum,  and  when  the  furnace  stock 
house  is  sufficiently  nearby,  the  coke  is  delivered  directly  from  the  quenching 
car  into  stock-house  bins  with  a  minimum  of  breakage. 

Our  experience  has  fully  demonstrated  the  superior  merits  of  the  Semet- 
Solvay  system  of  main  division  walls  between  the  ovens  carrying  the  roof 
structure  in  a  permanent  manner  and  removing  all  load  from  the  thin  flue 
walls,  as  well  as  acting  as  a  reservoir  of  heat,  which  is  drawn  upon  when- 
ever the  oven  becomes  cooled  by  the  charge  of  fresh  coal.  The  independence 
of  the  flue  system  in  respect  to  the  main  structure  of  the  oven  permits  repairs 
to  any  oven  flue  to  be  made  without  shutting  down  any  of  the  adjacent 
ovens.  This  is  an  important  point  in  cases  where  the  coal  is  of  a  nature  to 
injure  the  flues,  necessitating  comparatively  frequent  repairs.  Some  of  the 
American  coals  that  have  been  developed  since  your  first  edition  have 
proved  to  be  quite  injurious  to  the  bricks  forming  the  flues.  In  such  condi- 
tions this  independence  of  each  oven  produces  quite  an  important  effect 
on  the  average  output  of  a  plant. 

The  rapid  exhaustion  of  the  Connellsville  field  has  awakened  new  interest 
in  the  retort  oven,  since  such  a  large  number  of  coals  throughout  this  country 
are  not  capable  of  producing  a  good  coke  in  the  beehive  oven,  and  the  coke 
users  must  turn  to  the  retort  oven  for  aid.  Many  of  the  coals,  while  suffi- 
ciently pure,  chemically,  do  not  give,  even  in  the  retort  oven,  a  structure 
11 


276  TREATISE  ON  COKE 

sufficiently  dense  to  support  the  furnace  burden  and  resist  the  dissolving 
action  of  the  hot  gases  in  the  top  of  the  furnace.  Experiments  have  proved 
that  this  structure  can  be  improved  and  made  entirely  satisfactory  by  grind- 
ing the  coal  to  a  size  of  \  inch  or  T3hr  inch  and  under,  and  compressing  the  coal 
either  by  ramming  or  pressure.  The  Semet-Solvay  Company  has  followed 
this  line  of  investigation  very  thoroughly  and  has  developed  a  compression 
machine  that  gives  very  satisfactory  results,  overcoming  many  of  the  diffi- 
culties that  have  made  the  use  of  the  machines  that  have  been' employed  on 
the  continent  of  Europe  very  unsatisfactory,  and  at  the  same  time  having  a 
capacity  as  to  time  of  compression  very  much  superior  to  any  other  machine. 
These  machines  are  being  installed  at  a  number  of  the  Semet-Solvay  plants. 
In  addition  to  the  improvement  in  the  physical  quality  of  the  coke,  the  use 
of  compression  increases  the  output  of  the  oven  from  10  per  cent,  to  15  per 
cent,  on  account  of  the  increased  amount  of  coal  that  can  be  charged. 

During  the  last  3  years,  the  production  of  illuminating  gas  from  by- 
product ovens  has  developed  remarkably,  and  now  the  process  is  operated 
very  successfully  in  a  number  of  places.  The  Semet-Solvay  Company 
has  been  delivering  illuminating  gas  of  18  candlepower  to  the  Detroit  City 
Gas  Company  for  about  a  year,  and  two  other  plants  are  being  fittecl 
up  for  this  purpose.  The  coke  oven  has  an  important  advantage  over  the 
old  retort  system  for  the  production  of  illuminating  gas,  namely,  that  in 
the  coke  oven  it  is  possible  to  make  use  of  the  well-known  fact  that  in  the 
distillation  of  coal  the  portions  of  the  gas  coming  from  it  during  the  early 
part  of  distillation  contain  much  the  greater  part  of  the  illuminating  bodies ; 
the  latter  portion  of  distillation  yields  mainly  carbonic  oxide  and  hydrogen. 
In  the  coke  oven,  it  is  easily  possible  to  use  the  gases  low  in  illuminating  power 
for  fuel  for  the  heating  of  the  ovens,  reserving  the  higher  illuminating  gas 
for  distribution.  In  the  ordinary  gas  retorts  this  separation  is  not  possible. 

In  the  by-product  side  of  the  operation,  improvements  have  been 
mainly  along  the  lines  of  greater  efficiency,  increased  yield  of  by-products 
owing  to  greater  perfection  of  apparatus  and  better  knowledge  of  the  condi- 
tions that  produce  the  largest  yield  of  by-products  consistent  with  the 
always  primary  point  of  the  best  possible  quality  of  coke.  The  distillation 
of  the  ammonia  has  been  very  greatly  developed,  so  that  now  all  apparatus 
is  of  much  higher  economic  efficiency,  while  permitting  the  easy  production 
of  crude  ammonia  liquor  up  to  25  per  cent,  ammonia  with  consequent 
saving  in  transportation  costs.  The  manufacture  of  aqua  ammonia  has 
also  been  developed  and  the  many  practical  difficulties  attendant  on  this 
manufacture  have  been  successfully  solved,  so  that  we  are  producing  at 
several  of  our  plants  aqua  ammonia  of  the  highest  commercial  quality. 

The  successful  development  of  the  by-product  oven  is,  of  course, 
dependent  on  the  ability  of  the  country  to  utilize  the  by-products,  so  as 
to  equal  in  consumption  the  very  rapid  increase  in  production.  With  the 
great  increase  in  the  cost  of  material  and  labor,  since  your  first  edition  was 
published,  the  costs  of  construction  and  operation  of  plants  of  by-product 
ovens  have,  of  course,  increased  proportionately,  and  it  is  necessary  that 
the  values  of  the  principal  by-products,  namely,  tar  and  ammonia,  should 
be  maintained  at  approximately  the  present  figures  in  order  that  the  con- 
struction and  operation  of  these  ovens  may  continue  to  be  attractive. 
Those  interested  in  the  markets  of  these  by-products  are  giving  the  most 
careful  study  to  the  development  of  their  use  in  new  fields,  but  at  present 
there  is  unquestionable  danger  that  the  very  large  amount  of  tar  and  ammonia 
that  will  come  on  the  market  in  the  next  year  will  seriously  affect  prices. 
There  is  no  doubt  that  the  consumption  of  the  country  will  in  time  catch 
up  with  the  production,  as  the  history  of  such  products  has  always  shown 
this  to  be  the  case,  but  it  is  quite  possible  that  there  will  be  a  considerable 
period  during  which  practically  all  profit  is  cut  off  from  those  operations, 
of  which  the  by-products  are  one  of  the  important  sources  of  profit. 

Yours  very  truly, 

W.  H.  BLAUVELT. 


TREATISE  ON  COKE  277 

Connellsville  Coke  From  Semet-Solvay  Ovens. — The  following 
report  of  tests  in  coking  Connellsville  coal  in  Semet-Solvay  retort 
ovens,  and  furnace  tests  of  the  coke  produced,  which  were  made 
for  the  Johnson  Company,  of  Lorain,  Ohio,  is  published  by  the 
special  permission  of  A.  J.  Moxham,  Esq.: 

A.  J.  MOXHAM,  ESQ., 

President  The  Johnson  Company, 
Lorain,  Ohio. 

Dear  Sir: — In  harmony  with  your  instructions,  dated  March  26, 
1895,  I  have  conducted  a  series  of  experiments  of  coking  Con- 
nellsville coal  in  Semet-Solvay  retort  ovens,  at  the  works  of  the 
Solvay  Process  Company,  near  Syracuse,  New  York.  The  coke 
made  in  the  ovens  was  shipped"  to  the  large  blast  furnace  of  the 
Buffalo  Furnace  Company,  at  Buffalo,  New  York,  and  its  value 
as  a  metallurgical  fuel  tested  in  this  blast  furnace  in  comparison 
with  the  best  quality  of  the  Connellsville  beehive-oven  coke,  from 
the  H.  C.  Frick  Coke  Company. 

The  main  scope  of  these  practical  experiments  was  to  deter- 
mine, from  actual  accomplished  work,  the  relative  economies  of 
the  manufacture  of  coke  in  these  two  types  of  coke  ovens,  with 
their  comparative  calorific  values  in  the  work  of  manufacturing 
pig  iron  in  a  modern  well-equipped  blast  furnace. 

At  this  time,  considerable  attention  is  being  directed  to  the 
economies  in  the  manufacture  of  coke,  with  the  saving  of  by- 
products in  retort  or  closed  ovens.  The  investigation  is  stimulated 
by  the  more  recent  improvements  made  in  the  construction  of  these 
ovens,  mainly  along  the  elements  of  securing  good  metallurgical 
coke  by  increased  internal  heat  in  the  ovens,  in  the  profits  secured 
by  saving  the  by-products  of  tar  and  ammonia,  and  by  the  increased 
percentage  of  coke  made  from  the  coal,  reducing,  in  proportion, 
the  percentage  of  impurities  in  the  coke. 

In  addition  to  these,  the  plan  of  these  ovens  has  been  simplified 
and  the  cumbersome  and  expensive  regenerators  and  recuperators 
omitted;  increased  oven  heat  has  been  secured  by  thinning  the 
inside  walls  through  which  the  flue  heat  is  transmitted  into  the 
coking  chamber  of  the  oven. 

With  the  use  of  the  best  coking  coals,  the  competition  between 
the  open  and  closed  ovens  is  quite  close  and  difficult  of  exact 
determination.  Other  things  being  equal,  the  main  effort  in  the 
manufacture  of  metallurgical  coke  in  the  retort  ovens  is  to  equal 
in  calorific  value,  in  blast-furnace  work,  the  standard  beehive- 
oven  coke.  But  in  the  manufacture  of  coke  from  the  lower  qualities 
of  coals,  especially  those  low  in  fusing  matters,  the  narrow  ovens 
have  undoubtedly  established  their  superior  value  in  this  respect. 

The  large  cost  of  the  retort  ovens,  as  compared  with  the  open 
or  beehive,  is  the  main  barrier  to  their  more  rapid  introduction. 
This  is  as  $3,100  in  the  former  to  $325  in  the  latter. 


278  TREATISE  ON  COKE 

To  make  the  tests  in  a  fairly  comprehensive  plan,  2,058jf  tons 
of  Connellsville  coal  was  shipped  from  the  Valley  mines  of  the 
H.  C.  Frick  Coke  Company  to  Syracuse,  for  the  initial  coking  test 
in  the  small  experimental  plant  of  twelve  Semet-Solvay  ovens  at 
this  place.  These  coking  tests,  as  well  as  the  subsequent  blast- 
furnace ones,  were  made  with  great  care,  as  the  importance  of  such 
determinations  evidently  demanded.  It  was  the  first  time  in  the 
industrial  records  that  beehive  and  retort-oven  coke,  from  Connells- 
ville coal,  were  compared  as  to  economy  in  cost  of  coking  and  rela- 
tive value  in  blast-furnace  work,  on  fairly  equated  conditions. 

The  following  analysis  of  the  Connellsville  coal  used  in  the 
coking  tests  at  Syracuse,  in  the  Semet-Solvay  retort  coke  ovens, 
exhibits  a  fair  average  of  the  coal  used: 

PER  CENT. 

Moisture,  212°  F 840 

Volatile  combustible  matter 31 . 600 

Fixed  carbon 59. 860 

Ash 7.700 

Sulphur • 820 

Phosphorus 008 

The  theoretic  percentage  of  coke  that  can  be  obtained  from  the 
above  coal  is  68  per  cent.  This  assumes  that  no  fixed  carbon  is 
consumed  in  coking  and  that  no  carbon  is  deposited  from  the  tar 
gas  in  the  oven.  In  the  modern  beehive  oven,  12  feet  by  7  feet, 
some  of  the  fixed  carbon  is  consumed  in  the  oven  by  the  admission 
of  air.  At  the  same  time,  the  percentage  of  its  coke  is  increased 
by  the  bright  glaze  of  deposited  carbon. 

Two  very  careful  tests  were  made  to  determine  the  percentage 
of  coke  made  in  the  Semet-Solvay  oven  from  Connellsville  coal. 

No.  1  test  charge,  9,200  pounds  of  coal,  produced  6,580  pounds 
large  coke,  164  pounds  breeze,  and  256  pounds  dust  and  refuse. 

No.  2  test  charge,  9,000  pounds  of  coal,  produced  6,349  pounds 
large  coke,  80  pounds  breeze,  and  198  pounds  dust  and  refuse. 

TEST  No.  1  TEST  No.  2 

PER  CENT.  PER  CENT. 

Large  coke 71 . 52  70. 55 

Breeze 1.78  .88 

Refuse,  pitch,  etc 2.63  2.20 

Total  coke 73.30  71.43 

Average  large  coke 71 . 035 

From  accurate  determinations  of  the  percentage  of  furnace 
coke  produced  from  Connellsville  coal  in  the  beehive  and  Semet- 
Solvay  coke  ovens,  it  was  found  as  follows:  beehive,  66  per  cent, 
of  large  coke;  Semet-Solvay,  71  per  cent,  of  large  coke. 

Taking  the  theoretic  coke  at  68  per  cent.,  it  is  evident  that  a 
loss  of  4.22  per  cent,  of  carbon  has  been  made  in  coking  in  the 
beehive  oven.  The  Semet-Solvay,  considered  from  the  same 
standard,  has  gained  4.41  per  cent,  of  carbon,  or  a  total  gain  of 
8.63  per  cent,  of  carbon  over  the  beehive  product. 


TREATISE  ON  COKE 


279 


In  the  beehive,  however,  the  carbon  deposit  consists  of  a  bright 
silvery  coating,  affording  efficient  protection  to  this  fuel  from 
carbon-dioxide  gas  in  its  descent  in  a  blast  furnace.  The  carbon 
deposit  in  the  Semet-Solvay  oven  is  a  dull-colored  deposit  of  car- 
bonaceous matter  from  the  tar  of  the  coal  in  coking.  Much  more 
carbon  is  deposited  in  the  beehive  oven  than  in  the  Solvay,  but  at 
the  same  time  much  more  carbon  is  consumed  in  the  open  oven. 

The  Semet-Solvay  oven  is  30  feet  long,  16^  inches  wide  inside 
coking  chamber,  and  5  feet  6  inches  high.  The  accompanying 
cross-section,  Fig.  22,  will  show  its  general  features.  It  is  con- 
structed with  dividing  walls,  arches,  and  superstructure  of  red 
brick.  It  is  noticeable  that  the  flue  tiles 
with  their  connecting  arch,  composing  the 
coking  chamber,  are  entirely  independent  of 
and  separate  from  the  red-brick  incasing 
structure;  this  secures  freedom  and  room 
for  expansion  in  the  lining  firebrick  work  of 
the  coking  chamber. 

The  16-inch  dividing  and  sustaining 
walls  perform  a  double  office  by  supporting 
the  structure  and  in  storing  heat.  The 
slight  cooling  of  the  oven  during  the  few 
minutes  occupied  in  discharging  the  coke  is 
quickly  restored  by  the  heat  stored  in  these 
incasing  red-brick  walls.  The  2|  inches  in 
thickness  of  the  inside  face  of  the  flue  tiles 
transmits  the  heat  from  the  combustion  of  the  returned  gas  in  the 
horizontal  flues  of  the  oven.  The  circuit  of  this  heat  is  continuous 
in  one  direction  and  can  be  regulated  at  pleasure. 

The  hot  gas  from  the  ovens  is  carried  under  boilers  to  generate 
the  necessary  steam  for  the  condensing  plant,  and  for  the  engine 
in  discharging  the  coke  from  the  ovens.  The  surplus  gas  can  be 
used  in  lighting  the  works,  or  in  any  other  way  that  may  be  required. 

The  horizontal  flues  in  this  oven  can  be  readily  examined  and 
cleaned.  They  convey  the  heat  in  an  even  and  direct  manner, 
avoiding  any  liability  to  the  injurious  concentration  of  heat  that 
is  sometimes  found  in  vertical-flue  ovens. 

In  considering  the  economies  of  this  type  of  oven,  it  is  important 
to  inquire  into  its  wearing  properties.  It  is  evident  that  the  red- 
brick walls,  arches,  and  superstructure  are  quite  permanent, 
requiring  no  special  attention  in  their  repairs.  The  firebrick  flue 
lining  of  the  oven  is  the  most  liable  to  breakage  and  wear.  The 
twelve  ovens  at  Syracuse  have  been  in  use  about  2  years,  and 
are  now  in  good  condition.  During  this  time  one  end  flue  tile  had 
to  be  replaced  from  a  crack  found  in  it.  It  is  quite  evident  that 
the  end  flue  tiles  are  liable  to  break  or  crack  from  the  frequent 
changes  in  temperature  at  the  doors  of  the  ovens.  The  inside  flues 
are  kept  at  a  nearly  uniform  heat  and  are  not  so  liable  to  crack. 


FIG.  22.     CROSS-SECTION 
SEMET-SOLVAY  OVENS 


280 


TREATISE  ON  COKE 


As  the  coke  is  cooled  on  the  outside  of  the  oven,  the  difference 
in  temperature  inside  should  not  seriously  affect  the  life  of  the 
flued  lining  tiles.  In  case  of  crack  or  breakage  of  these  jointed 
lining  tiles,  their  renewal  at  the  ends  of  the  oven  can  be  made  at 
a  small  cost  and  in  a  short  time.  The  renewal  of  the  inner  flues 
will  require  the  cooling  of  the  oven  as  well  as  the  ovens  on  either 
side  of  it.  This  is  the  most  serious  aspect  of  repairs,  involving 
considerable  expense  in  time  and  labor.  It  may  be  said,  however, 
that  the  renewal  of  the  inside  tiles  is  infrequent. 

The  coking  test  in  these  ovens  was  conducted  mainly  to  deter- 
mine the  minimum  time  required  with  maximum  heat  to  produce 
good  blast-furnace  coke.  The  various  tests  included  coking  periods 
ranging  from  18  to  26  hours.  It  appeared  that,  with  well-sustained 
oven  heat,  good  blast-furnace  coke  could  be  made  in  20  hours. 
This  was  the  standard  minimum  time  used  in  producing  the  coke 
for  furnace  test.  Some  coke  was  made  by  continuing  it  in  oven  26 
hours ;  this  produced  a  bright  hard  coke  evidently  equal  in  hardness 
of  body  to  the  beehive  coke  of  72  hours.  From  subsequent  experi- 
ence in  the  furnace  test  it  is  quite  probable  that  23  to  24  hours 
would  secure  a  firmer  coke,  which  would  bear  faster  furnace  driving. 
The  coking  tests  began  April  16,  and  closed  May  17,  1895. 
As  before  noted,  there  are  only  twelve  Semet-Solvay  ovens  at 
the  Solvay  Process  Works,  at  Syracuse,  New  York. 

The  analyses  of  Connellsville  and  Solvay  cokes,  made  at  the 
laboratory  of  the  Buffalo  furnace,  by  Mr.  O.  O.  Laudig,  chemist, 
are  as  follows: 

CONNELLSVILLE       SOLVAY 
PER  CENT.         PER  CENT. 

Moisture,  212°  F .19  1.25 

Volatile  matter 1.17  1.61 

Fixed  carbon 89.02  86.66 

Ash 9.62  10.48 

Sulphur 90  .77 

Analyses  of  Connellsville  coal  and  the  coke  made  from  it  in 
Semet-Solvay  ovens,  from  laboratory  of  the  Solvay  Process  Com- 
pany, by  Mr.  J.  D.  Pennock,  chief  chemist,  are  as  follows: 


Nc 

>.  3 

Nr 

>.  9 

Coal  Used 
Per  Cent. 

Coke 
Made 
Per  Cent. 

Coal  Used 
Per  Cent. 

Coke 
Made 
Per  Cent. 

Breeze 
Per  Cent. 

Moisture,  212°  F  

.470 

.200 

.000 

,070 

Volatile  matter  

30  .  460 

2.520 

29   020 

1-850 

4-73 

Fixed  carbon  

62  920 

87  .  480 

61.610 

87  070 

78,.  57 

Ash 

6  620 

10  000 

9-  370 

1  1  .  080 

16  70 

Sulphur 

900 

850 

.770 

750 

Phosphorus 

025 

,037 

017 

023 

TREATISE  ON  COKE  281 

In  several  tests  in  these  ovens,  the  coal  was  moistened  with 
1,  2,  and  3  per  cent,  and  up  to  5  per  cent,  of  water,  without  apparent 
change  in  the  quality  of  the  coke  produced  or  in  the  quantity  pro- 
duced from  this  coal. 

The  effect  of  the  temperature  of  the  oven  in  the  manufacture 
of  coke  is  well  understood.  For  dry  coals,  a  quickly  applied  high 
temperature  produces  the  best  possible  coke.  In  the  case  of  the 
richer  coals,  such  as  the  Connellsville,  a  more  moderate  heat 
secures  the  best  results  in  the  coke. 

During  the  progress  of  coking  at  Syracuse,  in  the  Semet-Solvay 
ovens,  frequent  tests  of  the  temperature  in  the  flues  and  interiors 
of  these  ovens  were  determined  by  the  use  of  the  German  Segar 
Cones.  These  have  been  recorded  as  follows: 

DEGREES  DEGREES 

FAHRENHEIT  FAHRENHEIT 

East  flue,  top. 2,130       East  flue,  bottom 2,138 

West  flue,  top 2,112       West  flue,  bottom 2,174 

East  flue,  center 2,222       Within  the  mass  of  coke  ..  1,994 

West  flue,  center 2,354       Above  the  mass  of  coke. .  .  1 ,958 

Temperature  tests  taken  in  the  beehive  oven  immediately 
above  the  coking  coal  gave  the  maximum  heat,  2,778°  F.,  from 
48-hour  or  furnace  coke. 

From  the  foregoing,  it  will  be  readily  seen  that  in  the  coking 
operations  of  these  ovens  the  application  of  heat  is  quite  different. 
The  long  time  required  in  drawing  the  coke  from  the  beehive  oven 
reduces  its  temperature  to  300°  or  400°  F.  The  operation  of 
coking,  therefore,  begins  under  a  mild  heat,  increasing  gradually 
until  the  high  maximum  is  reached  midway  in  the  operation,  pro- 
ducing a  hard-bodied  coke  with  fully  developed  cells. 

On  the  other  side,  the  rapid  discharge  of  the  coke  in  the  Semet- 
Solvay  oven  by  a  steam-engine  pusher  reduces  the  temperature 
very  slightly,  and  on  closing  the  doors  of  the  oven  for  a  fresh 
charge  of  coal  the  average  heat  is  rapidly  restored.  The  oven 
heat  is,  therefore,  applied  quickly  and  maintained  throughout  the 
time  of  coking. 

In  the  open,  or  beehive,  oven  the  coking  of  the  charge  of  coal 
begins  on  the  upper  horizontal  surface,  reaching  down  through 
the  charge  gradually  to  the  floor  of  the  oven.  The  coke  crystal- 
lizes in  a  vertical  columnar  structure  in  surfaces  at  right  angles  to 
the  horizontal  plane  of  the  oven.  In  the  Semet-Solvay  oven  the 
planes  of  crystallization  are  at  right  angles  to  the  vertical  side  walls 
of  the  oven,  and  consequently  in  horizontal  postures.  The  coking 
begins  at  the  oven  side  walls,  moving  gradually  to  the  central 
longitudinal  plane  of  the  oven,  where  a  line  of  demarcation  is 
developed  in  a  shelly  section  of  coke  of  inflated  physical  structure. 
The  pressure  of  the  charge  of  coal  in  the  narrow  oven  compresses 
the  cell  structure  of  its  coke,  making  it  more  dense  than  the  broad 
oven  with  shallow  charges. 


282 


TREATISE  ON  COKE 


The  general  structure  of  beehive  and  Semet-Solvay  coke  will 
be  noticed  in  the  sketches,  Fig.  23. 

A  beehive  oven  of  12  feet  in  diameter,  taking  the  inflated 
structure  of  coke  at  top  and  bottom  of  charge  at  3  inches,  will 
afford  85  per  cent,  of  good  coke  and  15  per  cent,  of  spongy  coke. 
The  Semet-Solvay  oven  makes  3  inches  of  spongy  shattered  coke 
in  the  middle  of  the  charge,  producing  81  per  cent,  of  compact 
coke  and  19  per  cent,  of  spongy  coke.  The  beehive  oven  will 
make  an  average  of  2  net  tons  of  coke  per  day.  The  Solvay  will 
afford  a  product  of  4  tons  per  day. 


BEEHIVE  COKE 
48  HOURS 


SEMET-SOLVAY  COKE 
20  HOURS 


Compact 


Spongy 


Dense  coke,  3  inches. 
Average  coke,  9  inches. 


Spongy  coke,  3  inches. 

Arrows  show  direction  of  coking. 


FIG.  23 


The  table  on  page  283  will  exhibit,  in  detail,  the  physical  and 
chemical  properties  of  cokes  made  in  these  typical  ovens. 

It  will  be  noted  that  the  Connellsville  coke,  used  at  the  Buffalo 
furnace  during  the  test,  was  from  the  Adelaide  works  of  the  H.  C. 
Frick  Coke  Company.  The  coal  used  in  making  coke  in  the  Semet- 
Solvay  ovens  at  Syracuse,  New  York,  was  shipped  from  the  Valley 
mines  of  the  H.  C.  Frick  Company. 

The  physical  determinations  of  the  Adelaide  coke  exhibit  a 
most  excellent  structure,  equaling  the  standard  coke  of  this  region. 
The  analysis  shows  its  superior  chemical  purity,  excelling  in  this 
respect  the  standard  coke. 

The  physical  tests  of  the  Semet-Solvay  coke  exhibit  the  increase 
of  density  in  the  retort  coke  as  compared  to  the  beehive.  These  are 
typical  examples  and  indicate  in  a  clear  and  definite  manner  the  con- 
dition of  coke  made  in  the  two  principal  types  of  coke  ovens.  The 
increase  of  cell  space  will  be  noticed  in  the  Solvay  coke,  from  the 
walls  of  the  coking  chamber  to  the  middle  of  the  oven.  The  average 
increase  in  density  of  the  Solvay  coke  over  the  standard  beehive 
is  12.7  per  cent.  The  compression  of  cell  structure  is  11 J  per  cent. 


U3 

1 

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P^ 

(a)  Standard  average 
(6)  Adelaide,  H.  C.  Frick  Co. 
Buffalo 
(c)  Section  at  oven  walls 
Intermediate  section 
Middle  section 
(d)  Used  at  Buffalo 

of  beehive  and  Semet-Solvay, 
D.  Pennock,  chief  chemist,  The 

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TREATISE  ON  COKE 


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The  by-products  are  estimated  a 
s,  9  cents.  In  the  above  compa 
t  is  assumed  that  these  will  not 


NOT 
and  surplu 
of  coke  ov 


The  chemical  analysis 
shows  a  fairly  clean  coke, 
but  exceeding  the  Adelaide 
coke  in  the  percentage  of 
ash.  This  analysis  dis- 
closes the  fact  that  the 
Solvay  coke  retained  1.61 
per  cent,  of  volatile  com- 
bustible matter,  as  against 
only  1.17  per  cent,  in  the 
Adelaide  coke,  an  increase 
of  3.76  per  cent.  This 
indicates  the  requirement 
of  a  longer  time  in  the  coke 
oven,  or  an  increase  of 
heat  to  reduce  this  volatile 
element. 

Retort  coke  should  be 
somewhat  harder  bodied 
than  open-oven  or  beehive, 
coke.  But  in  the  table 
on  page  283  they  are  just 
equal,  which  sustains  the 
demand  for  more  oven 
heat  or  longer  time  in 
coking  in  the  retort  oven. 
It  is  also  important  to 
reduce  the  percentage  of 
the  inflated  sections  of 
coke  in  the  middle  of  the 
oven.  It  is  submitted  that 
by  widening  the  oven 
chamber  to  20  inches,  the 
ratio  of  shattered  to 
solid  coke  would  be  largely 
reduced. 

The  tabulated  state- 
ment on  this  page  will  ex- 
hibit the  relative  costs  and 
economies  in  plants  of 
beehive  and  Semet-Solvay 
coke  ovens,  to  produce 
300,000  net  tons  of  blast- 
furnace coke  per  year, 
using  Connellsville  coal. 

The  breeze  from  han- 
dling the  Solvay  coke  is 
much  less  than  that  from 


TREATISE  ON  COKE  285 

the  beehive  coke.  Little  waste  is  found  in  careful  handling  of 
Semet-Solvay  coke. 

The  Buffalo  furnace,  of  the  Buffalo  Furnace  Company,  is  a 
modern  blast  furnace,  18  feet  at  bosh  and  80  feet  high.  It  has 
three  hot-blast  stoves,  18  feet  by  70  feet,  of  the  Cowper-Kennedy 
type.  The  blowing  engines  have  surplus  power  and  can  increase 
the  pressure  of  blast  to  meet  the  requirements  of  different  densities 
of  fuels.  The  plant  is  located  on  the  bank  of  the  Buffalo  River,  on 
the  west  end  of  Hamburg  Street,  and  receives  its  ore  stock  direct 
from  the  lake  boats. 

The  limestone  for  fluxing  comes  from  Canada,  from  the  upper 
members  of  the  Helderberg  formation,  and  is  most  excellent  for 
this  purpose.  Many  of  its  sections  are  highly  saturated  with 
petroleum.  The  composition  of  limestone  is  as  follows: 

PER  CENT. 

Carbonate  of  lime 97 . 45 

Carbonate  of  magnesia 1 . 40 

Oxide  of  iron,  alumina,  etc 50 

The  coke  used  at  this  furnace  is  supplied  by  the  H.  C.  Frick 
Coke  Company.  It  was  especially  noted  as  the  very  best  quality 
of  furnace  coke;  evidently  it  had  been  carefully  selected,  as  no 
black  ends  were  visible  in  the  supply  examined.  It  was,  therefore, 
quite  manifest  that  the  best  Connellsville  beehive  coke  would  be 
used  in  the  competitive  test  with  the  Semet-Solvay  coke.  The 
whole  furnace  plant  is  ably  managed  by  Mr.  F.  E.  Bachman. 

Immediately  before  the  commencement  of  the  coke  tests,  the 
furnace  was  banked  a  short  time  to  give  opportunity  for  cleaning 
the  hot-blast  stoves.  It  was  assumed  that  a  few  days  after  resump- 
tion of  work,  the  furnace  would  regain  its  normal  condition.  It 
did  not,  however,  attain  uniform  work  throughout  most  of  the  time 
of  these  tests,  but  it  is  proper  to  submit  that  the  irregularities 
in  its  working  were  about  equally  distributed  over  the  periods  of 
the  use  of  beehive  and  Semet-Solvay  cokes;  possibly  somewhat 
more  during  the  use  of  the  Semet-Solvay  coke. 

This  furnace  is  run  chiefly  to  make  open  foundry  pig  iron, 
and  this  was  its  product  during  the  time  of  these  coke  tests,  with 
some  exceptions,  when  a  denser  metal,  denominated  "holly,"  was 
produced. 

The  mixture  was  changed  slightly  during  the  tests,  but  was  on 
an  average  as  follows: 

POUNDS 

Marquette  iron  ore 17,000 

Winthrop  iron  ore 878 

Rex  iron  ore * 636 

Florence  iron  ore 1 ,050 

Queen  iron  ore 672 

Total..  20,236 


286  TREATISE  ON  COKE 

This  mixture  gave  an  average  product  of  57.29  per  cent,  of 
foundry  pig  iron. 

The  weights  of  the  coke  charges  averaged  as  follows: 

POUNDS 

Beehive,  Connellsville 10,923 

Retort,  Semet-Solvay 11 ,830 

The  limestone  charges  averaged  as  follows : 

POUNDS 

For  Connellsville  coke .    3,300 

For  Semet-Solvay 3,600 

The  general  table  of  blast-furnace  operations,  on  page  287,  will 
exhibit  the  results  of  these  tests,  with  Connellsville  beehive  and 
Semet-Solvay  cokes. 

These  general  results  require  and  will  be  adjusted  subsequently, 
so  as  to  give  to  each  test  the  true  results  of  its  work  as  accurately 
as  can  be  determined. 

The  test  of  the  Connellsville  beehive  coke  began  May  12,  at  6 
o'clock  A.  M.,  and  closed  May  16,  at  5  o'clock  p.  M.  The  Semet- 
Solvay  coke  test  began  at  the  close  of  the  beehive  coke  and  ended 
May  22,  at  2  o'clock  A.M.  Approximately  5  days  were  allotted  to 
each  kind  of  coke. 

Samples  of  each  kind  of  coke  were  submitted  to  severe  tests  for 
moisture,  in  a  neighboring  foundry  core  oven,  and  resulted  as 
follows:  Connellsville  beehive  coke,  973 J  pounds  dried  to  956 
pounds;  loss,  1.830  per  cent.  Semet-Solvay  coke,  1,174J  pounds 
dried  to  1,114J  pounds;  loss,  5.385  per  cent.  The  heat  of  the  core 
oven  was  not  determined,  but  it  was  estimated,  approximately,  as 
approaching  300°  F. 

Referring  to  the  analyses  of  the  beehive  and  Semet-Solvay 
cokes,  made  in  the  laboratory  of.  the  Buffalo  Furnace  Company 
and  at  the  Solvay  Process  Works,  it  will  be  noted  that  the  beehive 
coke  has  been  made  from  much  cleaner  coal  than  that  from,  which 
the  Solvay  was  made.  Taking  the  average  of  these  two  determina- 
tions for  the  Semet-Solvay  coke  would  give  it,  in  round  numbers, 
88  per  cent,  of  carbon,  and  the  beehive  89  per  cent,  as  charged 
into  the  furnace.  Equating  these  cokes  for  the  moisture,  it  will 
reduce  the  carbon  in  the  Semet-Solvay  coke  to  84  per  cent,  and 
the  beehive  to  88  per  cent,  of  efficient  available  carbon  for  furnace 
use,  allowing  for  the  volatile  matters  in  these  cokes. 

The  table  shows  that  there  was  little  waste  from  soft  coke,  as 
the  relations  of  the  two  gases,  CO2  :  CO,  were  found  to  be  as  1  :  2.47 
in  the  beehive  coke,  and  as  1  :  2.27  in  the  Semet-Solvay  product. 
Sir  I.  Lowthian  Bell  found  the  relations  of  these  gases  in  a  large 
test  of  Durham  beehive  coke  as  1  :  2.28,  and  in  Simon-Carves' 
retort-oven  coke  as  1  :  3.32. 

The  heat  in  the  furnace  during  these  tests  was  fairly  well 
sustained.  Closing  the  Connellsville  beehive  test,  a  disarrangement 


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288  TREATISE  ON  COKE 

of  the  stock  scale  reduced  the  limestone,  causing  a  slight  lowering 
of  temperature  of  furnace  at  the  opening  of  the  Solvay  coke  test. 

The  analyses  of  six  casts  of  beehive  and  Solvay  iron  will  afford 
comparison  of  heat  of  furnace  and  quality  of  pig  metal  produced, 
all  of  which  was  No.  2  pig. 

CONNELLSVILLE   SEMET-SOLVAY 
COKE  COKE 

Graphite  carbon 3 .  7GO  3 . 600 

Combined  carbon 170  . 180 

Silicon 2.770  2.150 

Phosphorus 283  .284 

Sulphur 049  .039 

Manganese 780  .780 

The  following  condensed  statement  will  show  the  stock  used 
and  pig  iron  produced  from  beehive  and  Semet-Solvay  cokes, 
during  these  tests: 

BEEHIVE  SEMET-SOLVAY 

COKE  TEST  COKE  TEST 

Iron  ore  used 4,260,080  pounds  4,711,190  pounds 

Limestone  used 729,400  pounds  870,700  pounds 

Coke  used 2,403,060  pounds  2,775,613  pounds 

Pig  metal  made 1,122  tons  (of  2,300  pounds)  1,205  tons 

Coke  per  pound  of  iron  .956  pound  1.028  pounds 

Equating  the  conditions  of  these  cokes  and  eliminating  excess 
of  moisture,  the  coke  per  pound  of  iron  will  be  for  beehive  .938 
pound,  and  for  the  Semet-Solvay  .972  pound. 

When  the  further  fact  is  taken  into  consideration  that  the  Semet- 
Solvay  coke  contained  an  average  of  10.17  per  cent,  of  ash,  while 
the  beehive  had  only  9.62  per  cent,  of  this  impurity,  the  quantity 
of  each  kind  of  coke  to  smelt  1  ton  of  foundry  metal  is  substantially 
equal,  and  the  amount  of  coal  used  as  Semet-Solvay  coke  is  propor- 
tionably  reduced. 

Introducing  the  factor  of  relative  proportions  of  coke  made 
from  a  pound  of  coal  in  the  two  types  of  ovens,  the  comparison 
becomes  as  follows:  beehive,  1.421;  Setnet-Solvay,  1.389. 

The  different  grades  of  foundry  metal  made  during  the  5-day 
test  by  each  kind  of  coke  are  as  follows: 

No.  1  No.  2   No.  2  PLAIN  No.  3  RAGGED  TOTAL 

TONS  TONS          TONS  TONS  TONS  TONS 

Beehive 20           357              480  237  28  1,122 

Solvay 73           487             461  156  28  1,205 

It  will  be  noted  that  the  Solvay  coke  products  in  pig  iron,  Nos. 
1  and  2,  give  560  tons,  and  the  beehive,  377  tons.  The  lower 
products  of  Solvay  coke  in  No.  2  Plain,  No.  3,  and  Ragged  give 
645  tons,  against  745  tons  from  the  beehive  coke.  The  difference, 
therefore,  in  the  heats  afforded  in  the  metal  made  by  beehive  and 
Solvay  coke  is  fairly  in  favor  of  the  latter. 

The  most  vital  inquiry,  in  these  competitive  tests,  consists 
in  the  relative  physical  properties  of  these  cokes  to  stand  rapid 


TREATISE  ON  COKE  289 

driving  in  the  furnace.  It  was  found  that  usually  the  Connellsville 
beehive  coke  could  take  a  blast  from  51  revolutions  of  engine, 
while  the  Solvay  coke  reached  its  maximum  at  48  revolutions, 
a  reduction  of  5.88  per  cent. 

The  tabulated  statement  of  furnace  operations  during  these 
tests  shows  that  the  largest  output  of  pig  iron  from  beehive  coke 
was  259  tons,  and  from  Solvay  coke  244  tons;  a  decrease  in  daily 
product  of  the  latter  of  5.79  per  cent.,  which  is  in  harmony  with 
the  reduction  of  blast  when  using  the  Solvay  coke.  It  is  true, 
however,  that  the  Connellsville  beehive  coke  requires  to  be  reduced 
occasionally  to  48  revolutions  in  the  blast,  but  this  is  the  excep- 
tion rather  than  the  rule. 

The  analyses  of  the  gases  at  top  of  furnace  show  that  there  is  no 
loss  in  the  Solvay  coke  from  dissolution  in  its  passage  down  the 
furnace,  from  carbon  dioxide;  but  on  the  other  side  it  resists  this 
gas  with  more  firmness  than  the  Adelaide  coke.  No  temperature 
tests  were  taken  as  to  the  heat  of  the  gases  at  top  of  furnace,  but 
the  relations  of  CO2  to  CO  are  assuring  that  no  waste  from  dissolu- 
tion from  the  soft  or  spongy  portions  of  the  fuel  had  taken  place.  • 

From  the  denser  physical  properties  of  the  Solvay  coke,  it  was 
anticipated  that  an  increased  pressure  of  furnace  blast  would  be 
required  to  develop  its  best  qualities,  but  in  this  we  were  somewhat 
disappointed,  as  the  furnace  test  reversed  the  order  of  blast  in  a 
direction  just  opposite  to  the  one  anticipated.  The  conclusion  is 
evident  that  the  Solvay  coke  requires  more  heat  or  more  time  in 
the  oven  to  enable  it  to  stand  the  blast  in  driving  the  furnace  equal 
to  the  beehive  coke. 

In  making  the  coking  tests  at  Syracuse,  all  needed  facilities  were 
cheerfully  afforded,  by  the  chief  officials  of  the  Solvay  Process 
Company.  To  Mr.  Thomas  Morris,  superintendent  of  the  coke 
ovens,  I  am  indebted  for  many  helpful  suggestions  and  other  favors. 

During  the  progress  of  these  tests  at  Buffalo,  we  were  favored 
with  the  presence  of  Mr.  W.  B.  Coggswell,  managing  director  of 
the  Solvay  Process  Company,  as  well  as  by  Mr.  W.  H.  Blauvelt, 
fuel  engineer,  of  this  company.  The  Carnegie  Company  was 
represented  by  Mr.  James  Scott,  the  superintendent  of  the  Lucy 
Furnaces  in  Pittsburg;  also,  Mr.  Charles  McCrery,  manager  of  the 
Dunbar  Furnaces. 

Mr.  T.  B.  Baird,  vice-president  of  the  Buffalo  Furnace  Company, 
and  its  manager,  Mr.  F.  E.  Bachman,  afforded  full  opportunity  to 
secure  results  of  tests.  Mr.  Baird  was  especially  courteous  in 
extending  to  the  visitors  many  favors. 

Mr.  W.  T.  Richards,  of  Cleveland,  who  directs  the  management 
of  the  M.  A.  Hanna  Furnaces,  was  very  helpful  in  these  tests. 

In  conclusion,  it  may  be  submitted  that,  while  the  testing  time 
of  these  cokes  in  the  blast  furnace  has  been  necessarily  limited,  yet 
it  has  afforded  some  reliable  indications  of  the  relative  values  of 
retort  and  beehive  coal  in  the  manufacture  of  pig  iron. 


290  TREATISE  ON  COKE 

It  has  been  established  that  the  denser  coke  of  the  retort  oven 
could  not  be  driven  as  fast  in  the  furnace  as  the  more  open-celled 
beehive  coke,  in  relations  of  48  to  51. 

It  has  yet  to  be  shown  that  the  denser  retort  coke,  hardened  by 
increased  heat  and  time  in  the  oven,  can  be  made  to  stand  a  blast, 
proportionally  stronger  than  that  of  the  beehive  fuel,  to  equal  the 
furnace  output  of  the  latter  in  pig  metal. 

In  the  relations  of  density  of  fuel  to  speed  in  a  blast  furnace, 
the  fact  has  been  definitely  settled  that,  other  conditions  being 
equal,  the  speed  is  in  proportion  to  the  density  of  the  fuel.  This  is 
found  in  the  use  of  anthracite  coal  (which  is  a  natural  coke),  in 
blast-furnace  operations,  in  its  slow  calorific  energy,  as  compared 
with  open-celled  beehive  coke.  The  output  in  pig  iron  of  the  former 
to  the  latter  is  as  3,000  to  8,000  tons  per  month,  or  as  1  :  2.66. 

The  retort  oven,  however,  affords  advantages,  as  from  the 
Connellsville  coal  it  will  yield  71  per  cent,  of  large  coke  for  furnace 
use,  against  66  per  cent,  of  a  similar  product  of  the  beehive.  This, 
with  the  saving  of  by-products  by  the  retort  oven,  compensates  for 
the  difference  in  its  energy  or  speed  in  a  blast  furnace,  as  compared 
with  the  beehive  fuel. 

The  Semet-Solvay  coke  oven  has  been  designed  under  correct 
principles,  as  regards  wearing  properties  and  output.  Its  most 
distinguishing  property  is  in  its  rapid  work  in  coking,  which  is 
30  per  cent,  shorter  in  time  than  its  chief  competitors. 

Very  respectfully, 

JNO.  FULTON, 

Mining  Engineer. 

Johnstown,  Pa.,  July  2,  1895. 

The  Rothberg  by-product  coke  oven,  Fig.  24,  belongs  to  the  well- 
known  horizontal-flue  type  of  which  the  Semet-Solvay  oven  can  be 
considered  the  prototype.  This  oven  differs  from  the  Semet-Solvay 
in  that  a  vertical  wall  a,  Fig.  24  (b),  divides  the  flues  in  the  center 
into  separate  parts  and  that  standard  brick  are  used  instead  of 
special  tile.  Also,  one  set  of  flues  serves  two  adjacent  ovens,  while 
the  Semet-Solvay  has  a  solid  wall  between  two  ovens,  which 
necessitates  separate  flues.  The  oven  chamber  is-  about  33  feet 
long,  16  inches  wide,  and  6  feet  6  inches  high,  having  a  capacity  of 
7  tons  of  compressed  coal  or  5^  tons  of  loose  coal  per  charge.  The 
average  coking  period  is  30  hours,  but  has  been  reduced  to  24  hours 
on  test.  No  regenerator  chamber  or  hot  stove  is  used,  the  air, 
which  is  taken  in  through  openings  6,  b,  being  heated  in  the  recu- 
perative flues  c  and  d. 

Fig.  24  (b)  shows  the  flues  and  dampers.  From  the  recuperative 
flues,  the  air  passes  through  vertical  flue  e  and  meets  the  gas  from 
the  first  burner  at  /.  From  this  point,  the  flame  is  either  forced 
through  the  horizontal  flue  to  the  center  of  the  oven  and  back  in 
the  next  lower  flue,  or  is  allowed  to  -pass  directly  to  the  next  lower 


TREATISE  ON  COKE 


291 


292  TREATISE  ON  COKE 

flue  by  opening  the  damper  g  in  the  vertical  flue.  By  observation 
through  peep  hole  h,  it  is  easily  determined  which  course  the  gas 
should  take  to  keep  the  heat  of  the  oven  uniform.  The  second 
damper,  below  the  second  burner,  is  adjusted  in  a  similar  manner. 
The  gas  of  combustion  is  led  through  flues  i  and  k  under  the  oven 
and  back  through  /  and  m  to  the  stack  through  n  and  the  gas 
sewer  o.  The  stack  draft  is  regulated  on  any  oven  by  damper  p. 
By  admitting  the  gas  into  the  different  flues,  and  by  using  the 
regulating  dampers,  a  very  uniform  temperature  is  maintained. 
Air  can  be  admitted  through  any  of  the  peep  holes  in  case  it  is 
necessary  for  the  combustion  of  the  gas. 

The  advantages  claimed  for  these  ovens  are:  (1)  The  cost  of 
construction  is  reduced  by  the  elimination  of  the  regenerators  and 
hot-air  fans,  and  the  air  is  sufficiently  heated  in  the  inexpensive 
recuperative  flues.  (2)  The  ovens  are  easily  operated.  A  uni- 
form temperature  is  maintained  without  difficulty  by  the  use  of 
the  regulating  dampers,  as  every  part  of  the  oven  is  under  com- 
plete and  independent  control.  (3) '  Operating  expense  is  reduced 
by  cutting  out  the  elaborate  hot-air  system. 

This  type  of  oven  was  first  used  at  the  Lackawanna  Iron  and 
Steel  Company's  plant  at  Lebanon,  Pennsylvania,  in  1903,  where 
an  experimental  battery  of  five  ovens  was  erected.  The  results 
obtained  from  this  small  battery  caused  the  Lackawanna  Company 
to  install  the  oven  at  their  Buffalo  plant,  282  ovens  have  been 
built  and  470  more  are  in  course  of  construction  at  that  place. 

The  A.  Hiissner  Coke  Oven.* — This  is  one  of  the  forms  of  coke 
ovens  built  mainly  for  the  saving  of  by-products  in  coking.  Mr. 
Hiissner,  the  inventor,  is  one  of  the  early  experts  in  the  successful 
work  of  securing  these  products. 

The  flues  in  this  oven  are  horizontal;  similar  in  this  respect  to 
Simon-Carves  and  the  Semet-Solvay  ovens.  This  oven  differs 
from  the  Coppee  and  Hoffman  types  in  the  posture  of  its  flues,  as 
they  have  the  vertical  posture.  The  horizontal-flued  ovens  afford 
a  very  uniform  diffusion  of  heat  in  a  simple  and  direct  manner. 

The  dimensions  of  the  flues  are:  length,  29  feet  6f  inches; 
width,  in  the  middle,  1  foot  lOf  inches,  with  a  certain  taper  to 
facilitate  the  mechanical  discharge  of  the  coke;  height,  5  feet 
10J  inches.  (The  original  Carves  oven  is  19  feet  8J-  inches,  by 
2  feet  5|  inches,  by  4  feet  9  inches  high.)  The  available  space  in 
the  Hiissner  ovens  is  88  per  cent,  of  the  total  space,  and  they  have 
a  charge  of  5£  tons  of  finely  sifted,  dry  coking  coal. 

The  charging  takes  place  by  four  holes  a,  a;  the  ends  are  closed 
by  doors  turning  on  hinges;  the  discharging  takes  place  by  the 
usual  steam  pushing  machine.  The  end  walls  between  each  two 
ovens  are  strengthened  by  buttresses  6,  Fig.  25  (a),  which  at  the 
same  time  prevent  air  from  entering  the  flues. 

*Lunge,  1887. 


TREATISE  ON  COKE 


293 


The  gases  are  aspirated  by  means  of  an  exhauster  through  the 
outlet  c,  and  are  forced  through  the  condensers  and  scrubbers, 
then  return  to  the  ovens  and  issue  by  the  tube  d  over  the  fire- 
grate e,  where  they  take  fire.  The  fire  gases  travel  around  the  par- 
tition /,  rise  at  one  end  and  up  to  the  top  flue  g,  and  descend 
through  three  horizontal  flues  and  the  snore  hole  h  into  the  main 
flue  i.  The  mouth  of  the  gas-inlet  pipe  d  is  an  annular  double 
tube,  like  a  Bunsen  burner;  while  the  inner  tube  conveys  the  air 


(*) 


FIG.  25.     HUSSNER  COKE  OVEN 


for  combustion,  the  combustible  gas  issues  through  the  annular 
space,  and  both  enter  at  the  same  time  into  e.  Owing  to  the  dis- 
tance that  the  products  of  combustion  have  to  travel  before  they 
reach  the  main  flue  i  (about  100  feet  in  Carves  oven),  they  were 
formerly  cooled  too  much,  while  the  oven  bottoms  were  fluxed. 
To  avoid  this,  Htissner  (about  the  same  time  that  Carves  took  out 
his  new  patent  in  1883)  introduced  a  previous  heating  of  the  air 
to  about  300°  centigrade  in  the  flues  /;  it  is  then  conveyed  through 
the  small  flue  k,  contained  in  the  buttress  b,  partly  through  /  into 
the  grate  space  e,  partly  through  /  into  the  top  flue  g,  and  in  both 


294  TREATISE  ON  COKE 

places  gets  mixed  with  gas.  This  does  not  seem  to  have  met 
with  complete  success;  but  after  adding  further  gas  inlets  at  m 
and  m,  the  fire  on  the  grate  e  could  be  left  out,  the  gases  sufficing 
for  heating  the  retorts. 

The  cost  of  erecting  a  set  of  one  hundred  Hiissner  ovens  in 
Gelsenkirchen,  Westphalia,  according  to  a  published  balance  sheet, 
was:  For  ovens,  buildings,  machinery  and  iron  wall,  railroads 
and  water  supply,  £300  per  oven  ($1,500).  The  ovens  are  charged, 
at  intervals  of  60  hours,  with  5^  tons  of  coking  coal. 

They  are  stated  by  Hiissner  to  yield  from  good  coking  coal  as 
follows : 

PER  CENT. 

Large  coke 75 . 00 

Small  coke 80 

Coke  breeze 1 . 20 

Tar 2.77 

Sulphate  of  ammonia 1.10 

A  recent  statement  claims  that,  from  a  charge  of  7  tons  of 
coking  coal,  5  tons  of  coke  is  obtained  in  48  hours;  this  shows  a 
product  of  71.43  per  cent,  of  coke. 

It  is  also  submitted  that  all  the  surplus  heat  from  the  ovens 
can  be  returned  to  the  steam  boilers,  or  other  uses,  affording  a 
much  greater  heat  supply  than  is  usually  obtained  by  the  use  of 
a  portion  of  the  gas,  deprived  of  the  by-products,  to  the  steam 
boilers.  In  the  Otto-Hoffman  ovens,  40  per  cent,  is  estimated  for 
use  in  generating  steam. 

It  is  evident  that  this  oven,  from  the  substantial  method  of 
its  construction,  its  horizontal  flues  and  its  simple  requirements 
in  its  operation,  is  destined  to  meet  the  wants  in  the  coking  of  a 
wide  range  of  the  several  qualities  of  coking  coal,  with  slight 
revision  in  its  dimensions. 

The  Bernard  Coke  Oven. — Fig.  26  shows  the  Bernard  system 
of  retort  coke  ovens.  This  oven  was  designed  for  producing  coke 
only,  but  when  it  is  further  desired  to  save  the  by-products  of  tar 
and  ammonia,  the  arrangement  of  the  flues  is  changed  from  the 
vertical  to  a  horizontal  position. 

The  first  trial  battery  of  these  ovens  consisted  of  thirty-six 
ovens;  the  second  and  more  recently  completed  addition  has 
eighteen  ovens,  making  in  all  fifty-four  coke  ovens  at  this  plant. 
These  ovens  were  built  by  Mr.  Walter  M.  Stein,  of  Primos,  Pennsyl- 
vania, for  the  New  Glasgow  Iron,  Coal,  and  Railway  Company,  of 
Nova  Scotia. 

The  coke  is  discharged  from  the  ovens  by  a  steam  ram  every 
40  to  48  hours,  according  to  the  regularity  or  irregularity  of  the 
supply  of  coal  for  charging.  Each  oven  is  charged  with  6  gross 
tons  of  crushed  and  washed  coal,  containing  12  per  cent,  of  mois- 
ture. The  total  daily  charge  for  the  fifty-four  ovens  is  162  gross 
tons  of  coal. 


fl 

,26 


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296 


TREATISE  ON  COKE 


The   one-half   of   the    ovens,    twenty-seven,    discharged    daily, 
gives  from  each  oven  2J  tons  of  marketable  coke,  with  less  than 


FIG.  27. 


GENERAL  PLAN  OF  FIFTY-FOUR  RETORT  COKE  OVENS,  BERNARD'S  SYSTEM, 
PATENTED.     BUILT  BY  WALTER  M.  STEIN 


a,  battery  of  thirty-six  retort  coke  ovens,  Bernard  system;  b,  battery  of  eighteen  retort 
coke  ovens,  Bernard  system;  c,  chimney  for  a;  d,  chimney  for  b;  e,  side  of  coke- pushing  machine; 
f,  coke-discharge  side;  g,  tracks  for  windlass  for  raising  doors  of  ovens;  h,  tracks  for  larries 
for  charging  ovens;  i,  tracks  for  coke-pushing  machine;  /,  main  gas  flue  of  a;  k,  main  gas  flue  of 
b;  I,  a  r  flues;  m,  charging  holes;  n,  air  holes. 

3  per  cent,  of  moisture;  the  aggregate  daily  product  is  therefore 
60J  gross  tons  of  coke.     This  exhibits  a  yield  of  good  coke  of  fully 


TREATISE  ON  COKE  297 

75  per  cent.,  which  has  been  carefully  ascertained  by  coal  charged 
into  the  ovens  and  the  merchantable  coke  produced. 

As  Mr.  Stein  writes:  "The  cost  of  coke  making  at  Nova  Scotia 
is,  on  an  average,  15  cents  per  ton;  this  includes  taking  the  coal 
from  the  storage  bin,  charging  it  into  the  ovens,  pushing  the  coke 
out  of  ovens,  closing  the  oven  doors,  sealing  them  with  loam  and 
watering  the  coke.  This  work  is  performed  by  a  party  of  nine 
men;  they  could  with  ease  take  care  of  six  ovens  more  if  necessary. 
These  nine  men  are  all  ordinary  laborers,  with  the  exception  of 
one,  who  has  charge  of  the  pushing  engine.  The  coke  is  loaded 
on  charging  buggies  by  additional  men,  and  conveyed  to  the  blast 
furnace  by  an  endless  rope.  It  will  be  noted  that  a  force  of  nine 
men  is  required  for  a  plant  of  retort  coke  ovens,  whether  it  con- 
sists of  ten  or  sixty  ovens.  For  more  than  sixty  ovens,  an  addi- 
tional force  of  nine  men  is  necessary.  It  will  thus  be  seen  that 
the  maximum  economy  in  the  manufacture  of  coke  in  these  ovens 
is  only  secured  by  a  battery  of  sixty  ovens. 

"The  nine  men  operating  this  plant  of  fifty-four  ovens  are  dis- 
tributed as  follows.  Three  fillers  on  top  of  ovens.  Two  on  coke  side 
and  two  on  pusher  side  to  clear  the  doors,  level  the  charges  of  coal 
in  the  ovens,  and  seal  the  doors  with  loam.  One  man  is  required 
to  cool  the  coke  with  water  as  it  is  pushed  out  of  the  ovens.  The 
ninth  man  is  in  charge  of  the  engine  for  pushing  the  coke  out  of 
the  ovens.  A  bank  of  sixty  coke  ovens  is  considered  as  affording 
a  fair  daily  amount  of  work  for  the  nine  attending  workmen." 

The  cost  of  washing  the  coal  is  somewhat  below  5  cents  per 
ton  in  summer  and  10  cents  per  ton  in  winter,  indicating  a  yearly 
average  for  this  work  of  7?  cents  per  ton. 

The  whole  cost  of  labor  in  making  one  ton  of  coke  is  as  follows : 
work  at  washing  plant,  7J  cents;  work  at  coking  plant,  15  cents; 
making  a  total  of  22^  cents.  This  is  exclusive  of  repairs  to  ovens 
or  machinery,  supplies,  etc. 

Mr.  Stein  further  adds,  in  regard  to  the  cost  of  repairs  to  the 
ovens  per  ton  of  coke:  "I  beg  to  say  that  these  ovens  have  not 
cost  in  repairs  $100  since  they  were  started;  the  only  repairs  that 
will  be  required  are  the  door  blocks  on  the  discharge  side,  where 
some  scaling  of  brick  corners  occurs  by  the  use  of  water  in  cooling 
the  coke.  Occasionally,  a  hole  is  burned  in  bottom  of  oven  by  an 
irregular  supply  of  air.  At  long  intervals,  a  door  will  crack,  but 
this  is  infrequent. 

"As  a  general  rule,  retort  coke  ovens,  well  constructed  and 
skilfully  operated,  will  require  very  little  repairs  during  the  first 
10  years.  Three  years  ago,  during  a  long  strike  of  miners  in  Ger- 
many, I  had  the  privilege  of  examining  the  inside  of  numerous 
ovens  of  various  types,  and  they  generally  looked  well  inside, 
though  all  or  nearly  all  of  them  had  been  in  continuous  use  for 
about  10  years;  they  appeared  to  be  good  for  at  least  5  years  of 
additional  work." 


298  TREATISE  ON  COKE 

I  have  examined  a  sample  of  this  Nova  Scotia  coke;  it  is  quite 
firm  and  hard-bodied  and  is  a  fairly  good  furnace  coke.  This 
result  has  been  mainly  secured  by  the  admirable  preparatory 
work  in  washing  the  coal,  a  description  of  which,  by  Mr.  Stein,  is 
given  on  page  69. 

In  reference  to  the  cost  of  this  bank  of  retort  coke  ovens,  with 
coke-discharge  engine,  it  is  somewhat  difficult  to  say,  as  the  mate- 
rials for  the  experimental  plant  of  thirty-six  ovens  were  imported, 
which  would  add  to  the  cost.  The  principal  elements  of  cost  were 
as  follows : 

One  coke-discharging  engine $  3,000 

Iron  parts  of  coke  ovens,  complete 9,000 

Foundation  of  ovens  and  red  brick 8,000 

Firebrick,  all  imported 30,000 

Superintendence,  plans,  etc 5,000 

Total $55,000 

The  cost  per  oven  is  therefore  about  $1,000.  In  the  states  of 
Pennsylvania,  Ohio,  West  Virginia,  Missouri,  Illinois,  Alabama, 
and  Kentucky,  where  excellent  firebrick  is  readily  and  cheaply 
obtained,  the  cost  of  these  ovens  should  be  somewhat  under  the 
cost  above  stated. 

The  Brunck  Coke  Ovens.* — Since  the  time  of  the  experimental 
plant  described  by  the  inventor  (the  late  Franz  Brunck),  in  1894, 
a  number  of  installations  have  been  laid  down  on  this  system  in 
Rhenish-Westphalia  and  elsewhere.  In  general,  the  original  form 
of  the  ovens  and  conduits  has  been  retained,  but  a  great  improve- 
ment adopted  in  the  arrangement  of  the  double  flue,  whereby  the 
following  advantages  have  been  secured :  the  two  halves  of  the  oven 
can  be  heated  independently  of  each  other,  the  waste  gases  from 
each  half  being  led  away  separately.  Furthermore,  the  air  of 
combustion  can  be  heated  to  a  very  high  degree  by  being  directed 
upwards  through  the  checkerwork  of  firebrick  situated  between 
the  two  flues,  which  are  maintained  at  a  high  temperature  by  the 
waste  gases  from  the  oven ;  the  air  is  then  led  over  the  arch  of  the 
flue  and  traverses  the  cooling  channels  in  a  direction  contrary  to 
that  taken  by  the  furnace  gases.  In  this  manner,  a  large  part  of 
the  heat  escaping  from  the  ovens  is  returned  to  them  in  the  most 
direct  manner,  without  any  loss  by  radiation,  while  on  the  other 
hand,  the  heating  and  fusing  of  the  firebrick  of  the  flues  are  prevented. 

A  vertical  section  of  the  oven  and  heating  conduits  is  shown  in 
Fig.  28,  path  of  heating  gas  and  air  for  support  of  combustion 
being  indicated  by  arrows.  This  illustration  represents  one  of  the 
ovens  in  a  battery  of  one  hundred  and  twenty  at  the  Minister 
Stein  pit,  Gelsenkirchen.  Each  half  of  the  oven  is  heated  from 
the  bottom  and  the  two  sides,  the  flames  being  readily  accessible, 

*R.  Brunck  in  "  Stahl  und  Eisen." 


nn 

rh  rb 


FIG.  28.     THE  BK 


17303— vi 


FIG.  29.     INSTALLATION  OF  120  BRUNCK  COKE  O^ 

a,  Clarifying  tank;  b,  ammonia  works;  c,  tar  and  ammonia  tanks;  d,  steam  engine;  e,  water 

k,  centrifugal  separator;  /,  coke  pusher;  m,  o\ 


..o.:;::^-.:  •.;.;:«  .-:;>:;; ^- :».;•:  j.:;^-.-.;:^ 
K  COKE  OVEN 


J   L 


AT  THE  MINISTER  STEIN  PIT,  GELSENKIRCHEN 

ips;  /,  tar _and  ammonia  water  pumps;  g,  cooler;  fc,  cooler;  *,  washer;  /,  saturation  boxes; 
n  batteries  of  thirty;  n,  quenching  ramp 


TREATISE  ON  COKE  299 

easy  to  regulate,  and  enabling  the  heat  to  be  distributed  uniformly 
over  the  oven.  This  thorough  control  of  the  heating  is  highly 
important  for  the  supply  of  heat  to  the  upper  part  of  the  charge 
of  coal,  since  there  the  application  of  heat  is  from  the  sides  only, 
whereas  in  the  lower  part  of  the  oven,  heat  is  applied  from  both 
sides  and  bottom.  Again,  in  consequence  of  the  separate  removal 
of  the  waste  gases  the  draft  for  each  half  of  the  oven  can  be  regu- 
lated independently. 

As  can  be  seen  in  the  drawing,  the  heating  is  effected  from  both 
ends  symmetrically  toward  the  central  portion.  The  result  of 
this  method  of  conducting  the  heating  gases,  in  conjunction  with 
the  central  position  of  the  flue  underneath  the  oven,  is  that  the 
gas  in  the  oven  has  a  shorter  distance  to  traverse  than  is  the  case 
in  ovens  with  horizontal,  or  even  vertical,  heating  flues.  This  plays 
an  important  part  in  the  question  of  the  recovery  of  by-products 
and  the  yield  of  same,  since  the  longer  the  path  traversed  by  the 
gases  through  the  heating  conduits  the  greater  must  be  the  dif- 
ference between  the  initial  and  final  pressure  to  overcome  the 
resistance  opposed  to  the  movement  of  the  current.  As,  on  the 
other  hand,  the  pressure  of  gas  within  the  oven  is  nearly  constant 
throughout,  there  occurs  either  an  escape  of  gaseous  distillation 
products  from  the  oven  into  the  heating  conduits  or  of  air  and 
products  of  combustion  from  the  latter  into  the  oven,  it  being 
impossible  to  keep  the  oven  walls  gas-tight.  Both  these  occur- 
rences lead  to  waste — combustion — of  coke  and  by-products  and 
to  overheating.  Owing,  however,  to  the  short  distance  the  gas 
has  to  traverse  in  the  Brunck  oven,  it  becomes  possible  to  main- 
tain the  pressure  in  the  oven  and  heating  conduits  at  an  approxi- 
mate equilibrium,  and  thus  prevent  injurious  communication  and 
transfusion.  The  maintenance  of  this  condition  of  equilibrium 
is  also  greatly  facilitated  by  the  system  of  blowing  in  the  air  of 
combustion  by  means  of  ventilating  fans,  this  procedure  rendering 
the  air  supply  independent  of  the  natural  chimney  draft,  and 
enabling  the  pressure  to  be  adjusted  to  suit  requirements  through- 
out the  entire  system. 

The  structural  arrangement .  of  strong  central  pillars  between 
the  heating  conduits  of  each  pair  of  ovens  has  proved  successful 
during  an  experience  extending  over  seven  years.  These  pillars 
take  up  the  weight  of  the  oven  top  and  protect  the  oven  from 
abstraction  of  heat  by  the  adjacent  oven  when  the  two  are  in 
different  stages  of  the  coking  process.  As  explained  by  the  inventor, 
one  of  the  advantages  of  the  method  of  heating  by  means  of 
single  and  double  conduits  in  the  walls  is  that,  being  relieved  of 
the  weight  of  the  oven  top  by  the  central  pillar,  the  walls  can  be 
built  thinner  and  the  ovens  higher  than  is  possible  with  systems 
wherein  the  oven  walls  have  to  support  the  roof.  Owing  to  the 
more  rapid  conduction  of  heat  and  the  reduced  thickness  of  the 
charge  of  coal  to  be  coked,  the  operation  proceeds  more  rapidly, 


300  TREATISE  ON  COKE 

weight  for  weight,  and  the  capacity  of  the  ovens  is  therefore 
heightened  without  the  fireproof  fittings  being  exposed  to  as  much 
wear  and  tear  as  in  wider  ovens  with  thicker  walls.  Thanks  to 
these  favorable  conditions  and  the  uniformity  of  heating,  the 
Brunck  ovens  that  have  been  at  work  in  the  Kaiserstuhl  pit  for 
the  last  7  years  have  needed  but  very  little  repair.  The  removal 
and  replacement  of  portions  of  the  walls  and  sole  of  the  ovens  can 
be  effected  without  affecting  the  skeleton;  i.  e.,  the  central  pillars 
and  roof,  owing  to  the  fact  that  the  method  of  setting  the  brick- 
work has  been  chosen  with  a  view  to  such  contingency. 

In  addition  to  preventing  the  overheating  and  fusion  of  the 
brickwork  in  the  walls,  the  preliminary  heating  of  the  air  to  a 
high  degree  entails  the  advantage  of  enabling  an  excess  of  gas  to 
be  produced  even  in  the  case  of  coals  somewhat  deficient  in  gas- 
forming  constituents;  whereas,  in  ovens  where  the  air  is  but  slightly 
heated,  if  at  all,  the  whole  of  the  gas  is  consumed  in  heating  the 
ovens  themselves.  This  excess  production  naturally  extends  the 
limits  of  the  by-product  recovery.  The  excess  of  gas  obtained 
when  the  gas  content  is  19  to  20  per  cent,  forms  a  useful  reserve  in 
the  event  of  the  ovens  failing  by  reason  of  wet  coal,  bad  weather, 
or  the  intervention  of  Sundays  and  holidays.  Under  normal 
working  conditions  the  gas  finds  employment  for  lighting,  heat- 
ing, or,  more  recently,  as  a  source  of  motive  power.  For  the 
latter  purpose,  the  gaseous  distillation  products  of  the  Brunck 
coke  oven  are  particularly  adapted,  since,  in  consequence  of 
the  aforesaid  equilibrium  of  internal  pressures,  the  gas  is  not 
contaminated  with  products  of  combustion,  but  contains  its  high 
calorific  power. 

In  comparing  two  systems  of  coke  ovens,  it  is  evident  that 
preference  should  be  given  to  the  one  that,  given  the  same  coal  in 
both  cases,  furnishes  an  excess  of  gas  in  addition  to  waste  heat. 
If  from  the  gas  consumed  waste  heat  alone  is  produced,  the  degree 
of  efficiency  of  the  plant  is  lower,  because  waste  heat  is  only 
suitable  for  steam  raising,  and  even  when  devoted  to  that  use  is 
subject  to  loss  on  the  way  between  the  ovens  and  the  boilers. 
Moreover,  the  thorough  utilization  of  the  waste  heat  entails  a  much 
larger  heating  surface  for  the  boilers  than  is  required  by  gas  fuel. 
The  importance  of  heating  the  air  for  supporting  combustion  in 
the  ovens  led  to  the  adoption  of  a  method  for  utilizing  the  heat 
of  the  distillation  products  from  the  latter.  To  this  end  the  air 
and  hot  gases  are  conducted  in  contrary  directions  through  the 
special  apparatus,  wherein  the  latter  give  up  their  heat  to  the 
former;  and  as  the  volume  of  air  required  is  seven  to  eight  times 
that  of  the  gas  to  be  consumed,  the  large  quantity  of  gaseous 
products  formed  in  the  coking  process  is  suitably  cooled,  while  the 
air  is  correspondingly  heated.  There  is  thus  a  considerable  saving 
in  condensing  water,  or  in  the  expense  of  recooling  the  water  used 
in  the  condensers. 


TREATISE  ON  COKE  301 

All  coking  plants  of  the  Brunck  system  are  provided  with  a 
mechanical  leveling  apparatus  combined  with  the  coke  pusher 
(see  Fig.  28),  and  set  in  motion  from  the  latter  by  a  train  of  cog 
gearing.  This  does  away  with  the  old  laborious  task  of  leveling 
the  charge  by  hand,  and  the  attendant  inconvenience  occasioned 
the  workmen  by  the  gases  escaping  from  the  oven.  When  the 
machine  is  used,  the  surface  of  the  charge  of  coal  is  leveled  per- 
fectly throughout  the  oven,  whereas,  when  the  work  is  done  by 
hand,  the  upper  surface  generally  retains  some  of  the  conical  form 
assumed  by  the  charge  in  filling.  The  bar  of  the  machine  travels 
backwards  and  forwards  the  whole  length  of  the  oven  while  the 
charge  is  being  introduced,  and,  by  its  weight,  compresses  the 
charge  to  some  extent,  besides  doing  the  work  three  times  as  quick 
as  by  hand  labor.  As  a  result  of  this  compression,  the  weight  of 
the  charge  in  each  oven  is  increased,  and  at  the  same  time  the 
labor  of  three  or  four  hands  per  shift  is  saved  in  each  battery  of 
sixty  ovens. 

The  set  of  Brunck  coke  ovens  erected  at  the  works  of  Jules 
Chagot  and  Company,  Montceau-les-Mines,  is  noteworthy  on 
account  of  the  provision  of  a  special  device  for  fractionating  the 
oven  gases.  The  illuminating  power  of  these  gases  being  highest 
in  those  given  off  in  the  earlier  stages  of  distillation,  these  first 
fractions  are  drawn  off  through  a  special  conduit  to  the  gasworks, 
where  they  are  purified  and  utilized  for  lighting  the  town.  On 
the  other  hand,  during  the  second  period  of  the  coking  operation 
the  valve  leading  to  the  gasworks  conduit  is  closed,  the  gases  being 
delivered  to  the  condensing  plant. 

The  arrangement  of  the  newest  large  installation  of  Brunck 
plant,  viz.,  one  hundred  and  twenty  ovens  at  the  Minister  Stein 
pit,  Gelsenkirchen,  is  shown  in  Fig.  29.  The  engines  exhaust 
the  total  output  of  gas  from  the  ovens,  about  300,000  cubic  meters 
per  24  hours,  and  also  supply  power  for  the  ventilating  fans. 
The  blast  engines  supplied  with  the  Brunck  plant  are  character- 
ized by  smoothness  of  running  and  low  requirements  in  respect 
to  repairs,  being  thereby  superior  to  most  of  the  usual  rotary 
exhausts,  three  or  four  of  which  will  be  required  to  deal  with 
the  above  quantity  of  gas.  Being  compounded,  the  engines 
maintain  the  gas  at  such  a  constant  pressure  that  the  employ- 
ment of  a  gasometer  for  equalizing  the  pressure  becomes 
superfluous. 

As  shown  in  Fig.  29,  four  washers  are  sufficient  to  deal  with 
the  ammonia  in  the  gas  from  the  whole  one  hundred  and  twenty 
ovens  at  the  Gelsenkirchen  works,  and  replace  the  usual  numerous 
small  washers.  This  simplifies  the  arrangement  of  the  necessary 
conduits  and  facilitates  supervision  and  ease  of  working.  The 
various  machines  being  driven  direct  without  intermediate  shaft- 
ing, the  work  is  less  subject  to  interruption  in  the  event  of  repairs 
being  necessary  in  any  part. 


302  TREATISE  ON  COKE 

The  grouping  of  this  plant  is  as  simple  for  one  hundred  and 
twenty  ovens  as  generally  for  half  that  number.  The  Gelsen- 
kirchen  plant  is  capable  of  coking  250,000  to  260,000  tons  of  coal, 
with  10  to  12  per  cent,  of  moisture  per  annum,  and  of  turning  out 
2,800  to  2,900  tons  of  sulphate  of  ammonia,,  and  7,500  to  7,800 
tons  of  tar.  The  steam  boilers  for  utilizing  the  waste  gases  and 
excess  of  coke-oven  gas  have  a  total  heating  surface  of  1 ,400  square 
meters,  and  their  favorable  situation  immediately  behind  the 
center  of  the  four  groups  of  ovens  greatly  facilitates  that  utilization, 
besides  insuring  the  production  of  sufficient  steam  to  furnish  550 
tons  per  diem  for  working  the  pit ,  in  addition  to  satisfying  the 
requirements  of  the  condensing  plant. 

The  Bauer  By-Product  Coke  Oven. — By  means  of  the  accom- 
panying illustrations  and  description,  which  appeared  in  "Stahl 
und  Eisen,"  a  new  form  of  retort  coke  oven,  devised  by  Doctor 
von  Bauer,  which  has  been  adopted  by  the  firm  of  Fried.  Krupp 
after  a  year's  trial  at  the  Hanover  colliery,  owned  by  the  firm,  is 
shown.  Fig.  30  (a)  is  a  cross-section  through  the  center;  (b)  is 
a  longitudinal  section;  (c)  is  a  section  through  the  center;  (d)  is  a 
section  through  the  flues;  (e)  is  a  partial  section,  on  a  larger  scale, 
through  the  top  of  the  flues.  It  is  known  that  most  varieties  of 
coal  contain  more  gas  than  is  required  in  order  to  transform  them 
into  coke;  hence,  not  only  is  all  the  gas  unnecessarily  consumed, 
but  also  air  is  admitted  toward  the  end  of  the  process  through  the 
peep  holes  in  the  doors,  which  helps  to  lower  the  temperature  at 
the  expense  of  the  charge;  that  is  to  say,  at  the  commencement 
there  is  too  much  gas  and  too  little  air,  and  at  the  end  of  the  pro- 
cess the  reverse  condition  obtains,  notwithstanding  that  the  whole 
of  the  gas  is  consumed.  It  is  a  very  difficult  matter  to  regulate  the 
supply  of  air  and  give  the  proper  dimensions  to  the  gas  flues.  If, 
however,  there  is  a  means  of  supplying  the  gas  in  a  uniform  manner 
these  defects  are  removed,  and  in  addition  there  is  a  surplus  of 
unconsumed  gas,  which  is  of  more  value  than  spent  gas.  The 
system  under  consideration  enables  one  to  heat  the  air  in  an 
equally  uniform  manner,  and  to  increase  the  supply  of  air  and  gas 
as  the  increasing  temperature  of  the  oven  renders  it  necessary, 
thus  adapting  itself  to  the  exigencies  of  the  coking  process,  which 
at  first  requires  less,  and  later  more,  of  air  and  gas. 

The  method  can  also  be  applied  to  the  ovens  with  by-product 
recovery  in  which  gas  is  delivered  in  uniform  quantities  from  the 
gasometer. 

A  glance  at  the  drawings,  Fig.  30,  and  the  perusal  of  their 
description  will  show  that  the  Bauer  oven  can  be  worked  (1)  as 
an  ordinary  oven;  (2)  as  an  oven  with  condensing  apparatus; 
(3)  as  an  oven  worked  on  the  duplex  principle;  viz.,  of  abstracting 
the  gases  during  that  period  in  the  process  when  they  are  most 
rich  in  by-products,  and  allowing  subsequently  the  less  valuable 


TREATISE  ON  COKE 


303 


304  TREATISE  ON  COKE 

gas  to  pass,  without  being  cooled  and  afterwards  rekindled,  direct* 
into  the  flues.  By  this  method,  an  economy  of  both  heat  and  of 
gas  is  effected,  and  the  cost  of  the  by-product  plant  is  reduced,  as 
the  hottest  and  poorest  gas  is  not  treated. 

The  Bauer  ovens  will  take  a  charge  of  from  9  to  10  tons,  and 
the  average  coking  time  is  from  30  to  36  hours.  Considering 
their  output,  it  is  claimed  that  they  occupy  less  space,  and  the 
cost  of  working  is  less  than  is  the  case  with  some  of  the  other 
systems. 

The  ovens  are  rilled  through  the  charging  holes  a,  unless  it  is 
preferred  to  introduce  a  pressed  or  pounded  cake  of  coal  with  the 
aid  of  machinery,  and  thus  do  away  with  these  apertures.  (1)  When 
used  without  by-product  recovery  the  valves  to  the  exhauster  are 
closed  and  the  stones  that  close  the  main  flues  are  lifted.  (2)  When 
used  with  by-product  recovery  apparatus  the  valves  to  the 
exhauster  are  open  and  the  stones  that  shut  the  flues  are  down. 
(3)  The  duplex  principle  of  working  is  when  methods  (1)  and  (2) 
are  combined;  viz.,  at  first  with  and  afterwards  without  by-product 
recovery.  When  the  oven  is  without  the  by-product  system  the 
gases  reach  the  main  flues  b  through  three  apertures  c  and  thence 
pass  on  to  the  combustion  flues.  With  the  by-product  recovery 
plant  in  operation,  the  purified  gases  from  the  gasometer  pass  into 
the  mains,  and  thence  into  the  flues  through  six  openings.  With 
the  union  of  the  two  methods,  the  gases  from  the  gasometer  mix 
with  those  of  the  ovens  in  which  the  exhauster  is  not  working,  and 
then  flow  into  the  flues  through  six  apertures.  In  each  case  the 
flues  receive  gases  or  gas  mixtures  of  uniform  composition,  either 
the  crude  gas  disengaged  at  each  particular  phase  of  the  coking 
process,  or  the  return  gas,  or  else  the  return  gas  mixed  with  the 
gases  of  the  ovens  that  are  in  operation. 

The  gases  enter  at  the  top  ends  of  the  ovens,  pass  downwards, 
then  underneath  the  bottom  of  the  flues,  then  upwards,  and  finally, 
having  received  an  addition  to  the  quantity  from  the  mains,  pass 
once  more  in  a  downward  direction  to  reach  the  bottom  flue, 
situated  in  the  middle  of  the  oven,  and  thence  flow  to  the  boilers 
through  the  outlet  pipes.  The  ovens  operate,  therefore,  on  both 
sides,  namely,  from  the  ends  toward  the  center,  and  there  are  on 
that  account  two  inlets  for  the  gas.  Below  the  combustion  flues 
there  is  situated,  between  the  air  flues  that  are  underneath  the 
bottom  flues  of  the  oven,  a  main  air  flue;  this  receives  from  outside 
and  from  the  air  flues  both  cool  air  and  hot  air.  This  air  passes  up 
through  airways  that  are  located  between  the  combustion  flues, 
and  then  through  certain  small  ports  reaches  the  gases  that, 
from  the  main  flues,  have  passed  into  the  chamber  above  the  gas 
flues.  The  coal  in  the  oven  is  on  a  level  with  the  chamber  where 
the  gas  and  air  are  commingled.  In  places  where  the  gases  flow 
in  a  downward  direction,  the  previously  heated  air  is  introduced 
through  small  holes  underneath  the  flues,  and  in  order  to  admit 


TREATISE  ON  COKE  305 

fresh  air  certain  small  air  passages  are  effected  in  the  top  of  the 
oven  or  of  the  air  chambers. 

In  each  half  of  the  oven,  in  the  gas  flues,  the  fresh  air  is  admitted 
from  below  twice  and  emitted  from  above  as  hot  air,  and  once 
from  above  to  be  emitted  below  in  the  same  condition.  Those 
surplus  gases  that  are  not  consumed  in  the  combustion  flues  pass 
direct  from  the  mains,  previous  to  ignition,  into  a  transverse  duct, 
which  for  every  ten  retorts  connects  the  three  mains  together,  and 
from  this  duct  pass  through  the  main  outlet  to  the  boilers,  or  reach 
the  latter  by  a  separate  conduit  in  order  not  to  become  mixed  with 
the  spent  gases.  Parallel  with  the  return  gas  pipes,  there  run 
steam  pipes  for  the  purpose  of  moderating,  in  case  of  necessity, 
any  excessive  temperature  in  the  gas  mains,  or  in  order  to  main- 
tain any  particular  degree  of  heat  that  may  be  desired.  These 
pipes,  which  are  of  small  diameter  and  are  placed  above  the  oven, 
are  furnished  at  certain  intervals  with  nozzle-shaped  branches, 
furnished  with  taps  that  lead  into  the  mains.  The  position  of 
these  steam  pipes  is  shown  in  the  elevation,  although  they  are  too 
small  to  be  distinctly  indicated. 

The  battery  of  Bauer  ovens  consists  of  eight,  with  a  capacity 
of  9  tons.  The  coal  used  contains  12  per  cent,  of  water  and  67  to 
69  per  cent,  of  fixed  carbon  and  ash.  The  coke  yield  was,  taking 
the  average  of  the  year  during  which  the  ovens  were  worked 
experimentally,  73.2  per  cent.  Batteries  of  some  other  systems  in 
the  vicinity  were  worked  with  precisely  the  same  coal,  and  the 
highest  yield  of  the  old  or  the  most  recent  ovens  was  68  per  cent. 

The  normal  coking  time  for  one  of  Bauer's  ovens  is  30  hours. 
For  about  2  months  it  was  from  32  to  34  hours,  and  for  the  rest  of 
the  time,  as  special  men  were  not  told  off  to  attend  to  so  small  a 
battery,  the  time  has  been  48  hours;  as  soon,  however,  as  the  new 
installation  is  complete,  the  period  of  30  hours  will  be  adhered  to. 

An  oven  with  48-hour  charges  will  yield  in  1  year  (360  days) 
1,186.5  metric  tons  of  coke,  and  with  30-hour  charges  it  will  yield 
1,898.4  tons  of  coke;  that  is,  when  worked  without  by-product 
apparatus.  The  theoretical  yield  of  coke  has  been  given  above 
as  67  to  69  per  cent.,  or  as  smaller  than  the  actual.  Such  discrep- 
ancies are,  however,  not  infrequent.  At  Creusot,  in  Bauer's  ver- 
tical ovens,  working  with  a  mixture  of  coal  and  anthracite,  we  have 
a  yield  of  81  £  per  cent.,  although  theoretically  the  coke  contents 
are  put  down  as  82  per.  cent. ;  at  the  Hanover  colliery,  we  have  a 
yield  of  4  per  cent,  above  the  theoretical  one  as  before  stated, 
namely,  73.2  per  cent.  It  is,  therefore,  not  correct  to  merely  indi- 
cate the  charge  for  24  hours,  in  instituting  comparisons.  The  excess 
of  over  4  per  cent,  above  the  theoretical  yield  has  been  maintained 
by  Bauer's  ovens  regularly  throughout  the  whole  time  they  have 
been  in  operation,  that  is  to  say,  for  about  15  months;  and  these 
figures  are  not  simply  the  result  of  an  analysis  effected  in  the 
laboratory,  but  have  for  their  basis  the  total  amount  of  the  coke 


306  TREATISE  ON  COKE 

production  since  the  ovens  started  working.  At  the  Hanover 
colliery,  Doctor  Kassner,  Doctor  von  Bauer,  and  others,  are  of 
opinion  that  this  excess  in  the  yield  is  due  to  the  precipitation  of 
volatile  carbon,  which  is  absorbed  by  the  glowing  coke  in  the  last 
stages  of  the  process.  Notwithstanding  the  experiments  of  Kass- 
ner, many  are  skeptical  on  this  point,  and  further  investigations 
are  to  be  made.  The  fact  of  this  excess  of  the  yield  above  the 
estimate  is,  however,  well  established. 

The  advantages  claimed  for  these  coke  ovens  are  the  surplus 
of  gas  unconsumed,  the  smaller  space  that  they  occupy,  the  low 
working  expenses,  and  the  absence  of  any  smoke. 

Lowe  Coke  Oven. — In  response  to  a  request  for  information 
about  the  Lowe  oven,  the  following  has  been  received  from  the 
inventor,  Mr.  T.  S.  C.  Lowe: 

NORRISTOWN,  PA.,  July  14,  1903. 
MR.  JOHN  FULTON,  136  Park  Place,  Johnstown,  Pa. 

Dear  Sir: — Your  letter  of  June  26,  to  Mr.  Herbert  Cutler  Brown,  of  Los 
Angeles,  has  been  sent  to  me  with  the  request  to  write  you  concerning  my 
new  system  of  coke  and  gas  production,  and  it  gives  me  much  pleasure  to 
send  you  herewith  an  article  recently  published  in  the  Progressive  Age. 

I  have  been  much  interested  in  your  former  publications,  and  if  possible 
would  be  glad  to  furnish  you  with  accurate  tests  of  my  system,  but  so  far 
there  have  only  been  experimental  plants  built,  the  most  important  being 
that  of  the  Jones  &  Laughlin  Steel  Company,  and  unfortunately  it  will  take 
a  longer  time  to  get  accurate  information  from  that  source  than  you  will 
probably  have  before  issuing  your  proposed  publication,  for  the  reason  that 
it  has  been  found  necessary  to  let  down  heats  to  arrange  some  parts  of  the 
apparatus,  increasing  flue  space  and  stack  draft,  as  well  as  to  arrange  to 
prevent  the  indrafts  of  air  caused  by  warping  of  door  and  other  frames  of 
the  outer  casing.  This  is  easily  done,  as  soon  as  they  can  shut  down  the 
ovens  long  enough  to  do  the  work. 

These  first  ovens  have  been  in  operation  3  months,  and  it  is  desired  to 
continue  them,  since  it  serves  to  give  them  information  as  to  all  the  parts 
that  are  found  defective,  as  you  know  in  all  new  matters  something  will 
arise  that  can  be  bettered.  The  principle,  however,  works  perfectly,  and 
cannot  be  improved  on,  either  in  the  production  of  a  superior  quality  of  coke, 
or  the  saving  of  the  gases. 

In  about  2  weeks  from  npw,  however,  we  shail  start  up  a  new  plant 
better  arranged  for  making  tests,  at  Rockaway  Beach,  Long  Island,  and 
if  you  think  that  your  work  will  be  delayed  long  enough,  I  shall  be  pleased 
to  send  you  an  invitation  to  go  and  see  this  plant  operated,  for  I  am  sure  it 
would  be  an  interesting  feature  for  your  book,  and  afford  just  the  information 
that  is  now  needed  more  than  ever  concerning  the  production  of  metallurgical 
coke  and  gases  suitable  for  open-hearth  steel  work,  power,  etc. 

Very  sincerely  yours, 

T.  S.  C.  LOWE. 

New  Lowe  Coke-Oven  and  Gas-Making  System.* — This  new  proc- 
ess of  gas  making  has  now  passed  the  experimental  stages,  and  it 
is  a  proved  fact  that  a  superior,  hard,  heavy,  smokeless  fuel,  fully 
equal  to  the  best  anthracite,  can  be  made  in  any  locality  in  the 

*By  John  Haug  in  the  Progressive  Age,  April  1,  1903:  further  informa- 
tion upon  this  new  process  will  be  furnished  by  the  author  at  or  from  his 
office,  536  Bourse  Building,  Philadelphia,  Pennsylvania. 


TREATISE  ON  COKE  307 

world,  from  cheap  soft  coals,  and  while  doing  this  a  larger  volume 
of  gas  is  saved  than  by  any  process  heretofore  practiced.  This 
coke,  sold  under  the  name  of  "Lowe  anthracite,"  has  been  tested 
for  all  purposes  for  which  anthracite  has  been  employed,  and  in 
no  instance  has  it  proved  inferior,  but  in  many  cases  far  superior 
to  the  natural  anthracite.  To  devise  a  system  to  accomplish  this 
has  required,  on  the  part  of  the  inventor,  an  immense  amount  of 
work  and  study  and  the  possession  of  an  unusual  amount  of  scien- 
tific knowledge.  To  create  a  perfect  system  required,  first,  a 
thorough  study  of  the  older  methods.  The  old  beehive  system  was 
found  to  produce  a  good  hard  metallurgical  coke,  but,  as  a  rule, 
the  yield  is  only  from  50  to  60  per  cent,  of  the  coal  employed,  all 
the  rest  going  off  in  volatile  form.  It  was  noticed  that,  when 
care  was  taken  to  admit  air  in  the  best  proportions  for  securing 
high  heats,  the  coke  was  harder  and  better  and  the  yield  of  that 
oven  was  greater  than  when  this  care  had  not  been  exercised. 
The  reason  for  this  slight  increase  in  the  weight  of  coke  was  found 
to  come  from  the  deposit,  on  the  upper  portions  of  the  charge,  of 
carbon  dissociated  by  the  high  temperatures  from  the  heavy  hydro- 
carbons. Under  the  best  conditions  of  beehive  coke  making,  more 
than  50  per  cent,  of  the  combustible  gases  escape  from  the  tunnel 
head  of  the  oven  unconsumed,  which  of  course  accounts  for  the 
immense  volume  of  black  smoke  always  arising  from  coke  ovens 
operated  in  this  way.  It  was  this  knowledge  of  what  was  going 
on  at  the  different  stages  of  coking  under  this  system,  as  well  as 
the  knowledge  of  what  kind  of  coke  would  give  the  best  results 
in  blast  furnaces,  cupolas,  and  for  domestic  and  other  uses,  that 
showed  the  necessity  of  a  radical  change  in  this  most  important 
line  of  industry. 

Without  going  into  the  various  stages  of  how  he  arrived  at  his 
final  conclusions,  it  is  evident  that  Professor  Lowe  has  devised  a 
system  of  coke  and  gas  making  that  is  of  considerable  interest. 

The  first  requisite  was  to  retain  all  the  valuable  features  of 
the  beehive  ovens,  whereby  the  coal  is  coked  by  reflected  heat 
from  the  arches  of  the  ovens;  second,  to  maintain  continuously 
the  highest  possible  degree  of  heat  that  the  best  brickwork  would 
stand  without  injury,  that  all  of  the  heavy  hydrocarbons  might  be 
deposited  in  solid  form  during  their  passage  upwards  and  through 
the  hottest  part  of  the  coke;  and  third,  to  save  all  combustible 
gases  not  needed  in  keeping  up  the  necessary  heats. 

If  fairly  good  coke  could  be  made  in  the  old  way  without  act- 
ually burning  more  than  half  the  gases  arising  therefrom,  it  was 
certain  that,  with  a  properly  constructed  apparatus  by  which  the 
ovens  are  never  cooled  while  charging  coal  or  discharging  coke, 
and  where  the  air  admitted  for  burning  gases  comes  in  at  from 
2,000°  to  3,000°  temperature  instead  of  cold  air  as  in  the  old  system, 
it  would  be  easy  to  figure  that  a  much  larger  percentage  of  the  gas 
arising  from  the  coking  coals  could  be  taken  away  unburned,  and 


308  TREATISE  ON  COKE 

either  enriched  and  sold  as  illuminating  gas  or  employed  for  metal- 
lurgical heating  and  power  purposes  without  carbureting.  But 
this  required  an  entirely  new  construction,  and  the  plan  was  adopted 
which  resulted  in  the  ovens  being  heated  by  internal  combustion 
taking  place  directly  over  the  coal  to  be  coked. 

In  following  out  this  idea,  Professor  Lowe  has  devised  a  series 
of  ovens  a  built  within  a  single  steel  casing,  all  having  connecting 
flues  6,  with  large  regenerator  chambers  c  at  each  end  of  the  battery 
of  ovens,  and  also  a  steam  generator  d  and  stack  e  at  each  end  con- 
nected by  flues  /  and  g  to  the  superheaters,  as  shown  in  Fig.  31. 

To  properly  heat  a  large  plant  under  this  system  requires 
about  a  week,  but  after  the  heats  are  once  established  the  operation 
is  very  simple,  and,  so  far  as  the  brickwork  and  apparatus  generally 
are  concerned,  there  is  no  reason  why  they  should  not  last  10  to 
15  years  without  repairs.  Blast  furnaces  often  run  from  7  to 
10  years  without  closing  down  for  repairs,  and  their  work  is  much 
more  severe  than  that  of  coke  ovens. 

Under  Professor  Lowe's  system,  a  much  deeper  charge  of  coal 
is  thoroughly  coked  in  24  hours  than  in  the  beehive  oven  in  48  hours. 

From  four  to  twelve  of  these  ovens  are  built  in  each  battery. 
Therefore,  in  a  four-oven  plant,  one  oven  is  discharged  and  recharged 
every  six  hours;  in  a  six-oven  plant,  every  4  hours;  in  an  eight-oven 
plant,  every  3  hours;  and  in  a  twelve-oven  plant,  one  oven  every 
2  hours.  The  greater  the  number  of  ovens  in  one  battery,  up  to 
eight  or  twelve,  the  more  evenly  are  the  heats  maintained,  although 
most  excellent  results  have  been  obtained  in  a  four-oven  apparatus. 

In  order  that  the  reader  may  understand  how  the  gas  is  saved 
by  this  system  when  it  is  impossible  to  do  so  in  the  beehive  oven, 
we  would  state  that  the  heating  of  the  Lowe  ovens  and  taking  off 
gases  therefrom  are  alternating  operations,  while  the  coking  process 
is  continuous.  The  gas  arising  from  the  coking  coals  is  burned 
under  the  arches  of  the  ovens  and  over  the  coking  coal,  by  the 
admission  of  the  highly  heated  atmosphere  from  one  of  the  regener- 
ators, say,  for  30  minutes,  and  the  combustion  of  these  gases  is 
completed  while  passing  from  the  last  oven  into  and  among  the 
brick  checkerwork  of  the  regenerators  at  the  other  end,  and  the 
last  heats  are  taken  up  while  passing  through  open  iron  checker- 
work  in  entering  the  stack,  say,  for  30  minutes;  then  the  stack 
valve  is  closed,  and  water  being  sprayed  over  the  piled  cast-iron 
work,  large  volumes  of  steam  are  generated,  which,  while  passing 
through  the  checkerwork  brick,  is  so  highly  superheated  that  it 
does  not  in  the  least  check  the  coking  operations  of  the  coal;  and 
while  this  steam  passes  along  from  one  oven  to  another  through 
the  series  of  flues,  it  not  only  carries  with  it  the  volatile  hydro- 
carbons being  given  off  in  immense  quantities,  but  the  steam  itself 
is  decomposed  while  coming  in  contact  with  the  heavier  hydro- 
carbons and  the  flocculent  carbon  in  the  form  of  lampblack  or 
soot,  when  passing  through  the  highly  heated  brickwork. 


310  TREATISE  ON  COKE 

It  is  believed  that  in  the  larger  batteries  of  ovens,  for  every 
30  minutes  the  gas  is  burned  in  the  ovens,  the  gas-recovering 
period  can  be  extended  to  40  minutes;  thus,  over  57  per  cent,  of 
all  the  gas  arising  from  the  coking  coals  is  saved,  in  addition  to 
all  the  water  gas  that  the  more  solid  and  condensed  portions  will 
produce  by  their  admixture  under  these  high  heats,  leaving  no  tar 
to  be  provided  for.  In  fact,  the  inventor's  aim  has  been  to  convert 
everything  about  the  coal  into  either  a  high  grade  of  coke  or  gas 
in  a  combustible  form.  He  says  that,  in  apparatus  making  tar, 
it  is  always  at  the  expense  of  good  coke  and  large  volumes  of  gas, 
and  there  could  be  no  better  illustration  of  this  than  in  the  results 
obtained  in  distilling  coal  in  the  ordinary  gas-house  retorts,  for 
there  they  get  tar  in  such  quantities  that  the  gas  engineer  is  con- 
tinually hunting  better  methods  of  burning  the  tar,  either  under 
retorts  or  steam  boilers.  The  quality  of  Lowe-oven  coke  is  much 
superior  to  that  of  gasworks  coke.  The  writer  is  now  superintend- 
ing the  erection  of  a  number  of  Lowe  coke-oven  plants,  on  both  the 
Pacific  and  Atlantic  coasts.  The  largest  battery  of  ovens  yet 
built  is  that  at  the  Jones  &  Laughlin  Steel  Company's  plant  at 
Pittsburg.  They  are  built  inside  a  gas-tight  steel  casing,  having 
a  ground  space  for  the  ovens  and  superheaters  of  40  by  80  feet, 
and  contain  eight  ovens,  each  6  feet  6  inches  wide  by  38  feet  in 
length.  Each  oven  will  take  a  charge  of  coal  weighing  16  tons. 
The  brick  required  for  this  battery  of  ovens  was  about  500,000, 
including  the  regenerators  and  checkerwork,  but  it  is  found  that 
in  future  construction  this  can  be  considerably  reduced  without 
impairing  the  efficiency  of  the  ovens. 

The  steel  company  has  built  a  large  gas  holder,  and  gas  mains 
are  being  laid  to  their  various  open-hearth  steel  furnaces.  This  gas 
will  either  mix  with  or  supplement  the  natural  gas  of  which  their 
supply  is  now  so  short  and  the  price  so  high  that  they  have  been 
compelled  for  a  number  of  years  to  make  producer  gas  to  help 
them  out — which  is  both  troublesome  and  expensive.  These  ovens 
were  designed  to  be  ready  to  go  into  regular  operation  some  time 
in  April,  1903. 

A  test  of  the  ovens  in  producing  coke  was  made  about  the 
middle  of  January,  principally  to  settle  the  questions:  (1)  con- 
cerning the  ability  to  thoroughly  coke  so  thick  a  mass  of  coal 
(30  inches)  and  at  the  same  time  produce  a  satisfactory  quality 
of  coke ;  and  (2)  to  ascertain  whether  or  not  the  coke  could  be  dis- 
charged from  ovens  of  this  size  and  length  without  piling  up  in 
the  ovens.  Much  to  the  surprise  of  all,  the  coke  pusher  designed 
for  this  purpose  discharged  the  entire  mass  of  coke  in  a  solid  block, 
without  the  least  stoppage  or  hitch. 

These  were  two  very  important  points  to  a  concern  whose  coke 
production -was  3,000  tons  daily,  and  who  planned  to  increase 
that  output  to  4,000  tons.  To  make  4,000  tons  of  coke  daily  in 
beehive  ovens  would  require  the  maintenance  of  fully  1,800  of 


TREATISE  ON  COKE  311 

them,  and  as  it  required  one  man  to  three  ovens,  it  would  mean  a 
force  under  the  old  system  of  600  men  daily,  as  it  is  nearly  all  hand 
labor.  By  this  new  system,  fifty  men  will  be  amply  sufficient  to  do 
all  of  this  work,  leaving  550  to  go  into  other  more  useful  branches. 

While  making  the  short  test  of  the  ovens,  it  was  difficult  to 
ascertain  the  exact  increase  in  percentage  of  coke,  but  enough 
was  shown  to  satisfy  Professor  Lowe  that  the  increase  over  the 
beehive  yield  would  be  fully  20  per  cent.,  and  that  about  15,000 
cubic  feet  of  mixed  coal  and  water  gas  would  be  saved  per  ton  of 
coke  made;  or  60,000,000  cubic  feet  of  gas  while  producing  4,000 
tons  of  coke,  which,  counted  at  selling  rates  of  natural  gas  (10 
cents  per  1,000)  per  equal  number  of  heat  units,  would  amount  to 
$6,000  daily.  This,  with  the  800  tons  daily  of  pure,  solid  carbon 
saved  in  the  coke,  and  the  labor  of  550  men,  is  sufficient  to  give 
any  large  concern  like  this  a  great  advantage  over  its  competitors. 

The  time  consumed  in  discharging  coke  from  the  ovens  and 
recharging  the  coal,  and  quenching  and  loading  the  coke  into  cars, 
is  estimated,  under  favorable  conditions,  to  require  for  each  oven 
about  2£  minutes.  The  coke,  as  it  is  discharged  from  the  ovens,  drops 
into  an  immense  cage  capable  of  holding  13  tons  of  coke,  the  cage 
itself  weighing  6  tons.  This  is  picked  up  by  a  traveling  crane 
operated  on  an  elevated  railway,  and  run  to  a  tank  of  water  in 
which  it  is  immersed  for  about  15  seconds.  It  is  then  lifted  out, 
and  by  the  time  the  cage  is  swung  round  over  a  car,  the  internal 
heat  in  the  coke  has  so  driven  out  all  the  moisture  that  the  coke 
is  much  drier  than  when  quenched  with  hose  in  the  old  and  tedious 
way.  To  see  this  cage  with  its  load  handled  by  this  machinery 
one  would  think  it  had  but  a  feather's  weight. 

An  advantage  in  handling  coke  in  this  manner  is  that  there  is 
no  waste  in  the  form  of  breeze,  as  in  the  case  of  the  beehive  ovens, 
where  it  has  to  be  pried  out  with  bars,  and  consequently  broken 
up  considerably. 

The  coke  pusher  is  an  admirable  piece  of  machinery,  and  was 
designed  by  W.  B.  Hasbrouck,  who  at  present  has  charge  of  the 
Lowe  coke-oven  construction  work,  while  W.  Larramie  Jones,  of 
the  Jones  &  Laughlin  Steel  Company,  was,  I  believe,  the  origi- 
nator of  the  new  method  of  handling  and  quenching  the  coke  by 
machinery.  It  is  certain  that  they  are  taking  a  great  interest  in 
this  new  system,  and  it  will  not  be  surprising  if  in  time  it  will 
supersede,  not  only  all  their  beehive  coke  ovens,  but  the  entire 
coke-making  systems  the  world  over. 

Beehive  By-Product  Oven. — During  the  past  few  years  efforts 
have  been  made  to  use  the  beehive,  or  round,  coke  oven  in  the 
saving  of  by-products.  The  results  thus  far  have  not  been  assuring. 
Some  of  them  have  exhibited  considerable  ingenuity,  but  the 
section  of  this  oven  is  not  the  true  form  of  a  retort  It  is  undoubt- 
edly much  more  economical  in  first  cost  than  any  of  the  standard 


312  TREATISE  ON  COKE 

retort  ovens  with  by-product-saving  attachments;  but  it  cannot 
secure  as  good  results  along  this  line  as  do  the  standard  retort 
coke  ovens.  It  is  evident,  however,  that  the  coke  produced  in 
this  round  oven  will  inherit  a  much  more  desirable  physical  struc- 
ture in  its  coke  than  that  of  any  of  the  narrow  retort  coke-oven 
products. 

Fig.  32  shows  the  method  of  construction  of  these  round  by- 
product-saving coke  ovens. 

Doctor  Otto  builds  these  ovens  at  his  own  expense,  runs  them 
for  12  years,  taking  the  coal  from  the  mines  and  delivering  the 
coke  to  the  mine  company,  for  the  yield  of  tar  and  ammonia,  and 
at  the  end  of  the  term  surrenders  the  whole  plant  to  the  mine 
owners.  He  must  make  in  this  time,  from  the  value  of  the 
products  alone,  the  cost  of  the  ovens,  the  interest  of  the  capital 
invested,  and  the  legitimate  profit  of  a  manufacturer,  and  he  is 
successful  in  doing  it. 

MANUFACTURE  OF  COKE  FROM  COMPRESSED  FUEL* 

It  will  probably  be  admitted  that  the  best  coking  coals  on  the 
continent,  and  also  those  of  Great  Britain,  have  for  years  past 
been  getting  scarcer,  and  various  devices  have  been  employed  to 
improve  the  quality  of  the  result  in  coke  when  made  from  inferior 
seams.  A  few  years  ago  several  works,  chiefly  in  the  Saarbrticken 
district,  came  under  the  author's  notice,  where  a  systematic 
attempt  was  being  made  to  improve  the  quality  of  the  coke  by 
compressing  the  fuel  before  coking,  and  he  was  so  impressed  with 
the  improved  results  obtained  with  poor  coking  fuels  that  he 
undertook  experiments  on  the  same  lines.  It  is  proposed  in  this 
paper  to  embody  a  short  account  of  the  results  of  these  experi- 
ments and  the  benefits  derived.  It  may  be  said  at  once  that  the 
result  of  the  trials  made  showed  that  the  advantages  of  compression 
were  by  no  means  confined  to  the  poorest  coking  fuels. 

The  idea  of  compressing  fuel  for  coking  purposes  originated  on 
the  continent,  where  many  of  the  coals  coked  so  indifferently  that 
it  was  of  the  greatest  importance  to  adopt  any  method  that  gave 
a  prospect  of  improving  the  quality  of  the  resulting  coke.  It  had 
been  observed  that  the  coke  produced  from  the  lower  portions  of 
retort  ovens,  compressed  by  the  weight  of  the  superincumbent 
fuel,  was  superior  to  that  produced  from  the  upper  portions  of 
the  charge,  and  this  led  to  experiments  in  compressing  the  fuel  by 
various  means:  first,  by  stamping  in  the  oven  by  hand;  in  other 
cases  by  weighting  the  charge ;  and  from  this  the  practice  of  com- 
pressing in  a  box  outside  the  ovens  was  gradually  evolved,  the 
stamped  cake  being  afterwards  moved  out  of  the  box  into  the 
oven  by  mechanical  means. 

*By  John  H.  Darby,  Journal  Iron  and  Steel  Institute,  Vol.  1,  1902, 
page  26. 


TREATISE  ON  COKE 


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314  TREATISE  ON  COKE 

A  number  of  samples  taken  from  coking  fuels  in  various  parts 
of  Great  Britain  were  experimented  with.  The  degree  to  which 
slack  may  be  compressed  varies  with  its  character,  state  of  divi- 
sion, contents  of  moisture,  and  other  conditions;  and,  generally 
speaking,  it  was  found  that  the  weight  of  a  given  bulk  of  com- 
pressed fuel  in  an  oven  was  50  per  cent,  greater  than  fuel  charged 
in  the  ordinary  way  through  the  holes  in  the  upper  portion  of  the 
oven  and  leveled  by  hand.  Taking  into  account  the  side  clear- 
ance that  has  to  be  allowed  in  introducing  a  cake  of  fuel  into  an 
oven,  the  net  gain  in  weight  that  an  oven  of  given  capacity  would 
hold  varied  from  25  to  30  per  cent,  in  favor  of  compressed  fuel. 
But  it  was  found  that  the  compressed  fuel  coked  more  slowly 
than  the  uncompressed,  and  the  net  gain  in  production  of  coke 
per  oven  finally  amounted  to  between  10  and  12  per  cent,  in  favor 
of  the  compressed  charge. 

To  ascertain  the  difference  in  the  character  of  the  coke  from 
compressed  fuel  compared  with  uncompressed,  the  weight  of  a 
cubic  foot  from  a  solid  lump  of  coke  was  estimated,  and  it  was 
found,  in  the  case  of  three  samples  of  fuel  from  Durham,  that  the 
average  weight  per  cubic  foot  for  uncompressed  coke  was  63.37 
pounds  and  for  compressed,  80.88  pounds;  for  North  Welsh  uncom- 
pressed coke  the  average  weight  was  50  pounds  per  cubic  foot, 
compressed,  60.57  pounds;  South  Yorkshire  uncompressed  coke, 
53.9  pounds,  compressed,  57.9  pounds;  West  Lancashire  uncom- 
pressed, 58  pounds,  compressed,  66.4  pounds.  It  will  be  seen 
that  compressed  coke  is  considerably  denser,  in  addition  to  which 
the  following  advantages  were  noted:  (1)  The  breeze  or  small 
coke  was  very  much  reduced  in  quantity,  the  lumps  of  coke  were 
larger  and  firmer  and  in  a  marked  degree  bore  handling  without 
very  much  breakage.  (2)  The  process  of  charging  an  oven  by  the 
mechanical  means  in  use,  where  compression  of  fuel  is  adopted, 
occupies  much  less  time  than  the  old  method  of  charging  by  hand 
through  holes  in  the  top  of  the  oven;  in  fact,  the  time  is  reduced 
from  10  or  12  minutes  to  3  or  4  minutes,  so  that  the  objectionable 
smoke  is  largely  prevented  and  the  loss  of  by-products  is  less;  in 
fact,  in  some  cases,  the  yield  of  ammonia  has  been  increased  25 
per  cent.  (3)  Less  hand  labor  is  employed,  and  the  laborious  work 
of  forcing  the  wet  fuel  out  of  the  tubs  into  the  ovens  and  leveling 
the  charge  in  the  ovens  is  entirely  abolished,  while  the  clearance 
between  the  cake  of  fuel  and  the  side  of  the  oven  allows  the  free 
escape  of  the  gases  and  tends  to  prevent  undue  deterioration  of 
the  oven  walls. 

The  results  obtained  show  that  the  quality  of  the  coke  is  dis- 
tinctly improved  by  compression.  Such  improvement  is  natu- 
rally more  marked  in  some  fuels  than  in  others ;  but  from  a  large 
number  of  trials  made  with  many  of  the  English  fuels,  the  writer 
is  able  to  say  that  he  has  not  seen  any  instance  in  which  the  improve- 
ment made  by  compression  has  not  been  apparent.  Indeed,  he  is 


TREATISE  ON  COKE  315 

aware  of  a  case  in  which  compressed  coke  is  being  sold  in  the  open 
market  at  a  substantial  advance  on  coke  previously  made  from 
similar  uncompressed  fuel.  Even  with  the  best  coking  fuels  the 
results  obtained  seem  to  justify  the  outlay  in  equipping  a  plant 
for  compressed  fuel,  as  well  as  the  special  case  in  which  it  is  essen- 
tial that  the  fuel  should  be  compressed  in  order  to  produce  a  mar- 
ketable coke. 

In  reference  to  the  apparatus  employed,  it  is  unnecessary  to 
mention  the  machine  in  which  stamping  is  done  by  hand,  or  to 
describe  the  earlier  forms  of  mechanical  stamps  in  use,  and  it  will 
be  sufficient  to  illustrate  two  of  the  later  types. 

The  essential  parts  of  the  appliances  used  are  the  stamping 
machines  and  compression  boxes.  These  can  be  combined  in  a 
variety  of  ways  as  the  surroundings  may  demand.  For  example, 
there  are  the  combinations,  first,  of  a  compression  box  and  charger, 
built  with  a  superstructure  carrying  the  stamping  machine;  sec- 
ondly, a  compression  box  and  charger  with  stationary  stamping 
machine.  The  first  combination  may  be  described  generally  as 
suitable  where  the  machine  has  to  travel  for  a  considerable  dis- 
tance and  take  its  supply  of  slack  for  compression  at  a  number  of 
stopping  places,  stamping  operations  proceeding  during  the  travel- 
ing of  the  machine.  The  second  combination,  having  a  fixed  point 
for  the  fuel  supply,  allows  of  the  application  of  a  fuel-feeding 
device  as  presently  described,  and  offers  opportunities  for  saving 
both  time  and  labor.  In  fact,  under  favorable  conditions,  this  type 
of  machine  will  compress  and  charge  fifty  ovens  per  24  hours,  and 
it  is  probable  that  this  is  not  the  limit  of  the  modern  machines. 
With  both  these  types  of  machines,  in  many  instances,  a  coke- 
discharging  arm  may  be  conveniently  combined  with  the  compres- 
sion box,  in  which  case  two  men  are  able  to  control  the  operations 
of  pushing  the  coke  out  of  the  oven  and  charging  it  with  com- 
pressed fuel. 

NOTE. — If  the  principles  submitted  in  Chapter  VII  are  correct,  that  is, 
that  the  calorific  energy  of  blast-furnace  fuels  is  in  proportion  to  the  extent 
of  surface  presented  to  the  action  of  the  oxidation  gases  in  the  zone  of 
combustion  in  the  blast  furnace,  and  as  it  has  been  demonstrated  that  the 
most  dense  fuel — anthracite — is  the  lowest  in  value  for  rapid  heat  giving 
it  follows  that,  if  a  vigorous  fuel  is  a  desideratum  for  use  in  a  blast  fur- 
nace, then  any  element  of  compression  in  the  charge  of  coal,  tending  to 
densify  the  coke,  or  in  any  way  to  render  it  more  like  anthracite,  should 
be  avoided. — ED. 


CHARGING  AND  COKE-PUSHING  MACHINERY 

The  following  description  of  coke  pushers  and  ramming  machines 
is  taken  from  articles  by  Alfred  Ernst  and  Dr.  W.  B.  Rothberg, 
describing  the  by-product  coke  plant  of  the  Lackawanna  Iron  and 
Steel  Company,  at  Lebanon,  Pennsylvania,  appearing  in  Mines 
and  Minerals,  March,  1904. 


316 


TREATISE  ON  COKE 


Coal-Ramming  or  Compacting  Machines. — Eight  coal-ramming 
machines  K,  Fig.  33,  are  used  at  this  plant,  consisting  of  ham- 
mers working  in  steel  guides,  and  actuated  by  means  of  an  electric 
motor.  The  rammers  are  supported  on  the  framework  of  the  coal 
bin,  in  which  a  sufficient  allowance  is  made  for  strain  due  to  same. 
The  rammers  can  be  operated  in  any  desired  height  without  chan- 
ging the  stroke  of  the  machine.  A  controller  of  sufficient  capacity 
is  placed  in  a  convenient  position  for  the  operator. 


FIG.  33.     COAL  BIN  AND  RAMMERS 


Coal-Charging  Boxes. — Four  coal-charging  boxes  B,  Fig.  34, 
are  provided,  each  of  which  consists  of  a  base  plate  or  peel,  resting 
on  rollers,  having  a  rack  attached  thereto,  and  engaging  with 
suitable  pinions  and  gearing  for  moving  the  peel  into  the  oven 
with  a  cake  of  compressed  coal.  The  sides  and  ends  of  the  box 
are  of  sufficient  height  to  form  a  cake  of  coal  for  the  ovens.  The 


TREATISE  ON  COKE 


317 


318  TREATISE  ON  COKE 

front  end,  or  end  nearest  the  ovens,  is  formed  of  two  doors  with 
a  suitable  locking  device  connected  directly  to  the  operator's  cab 
by  means  of  locking  levers.  The  rear  end  is  stationary  and  is  built 
up  rigidly  on  the  lower  framework  of  the  machine.  The  sides  of 
the  box  are  supported  by  short  links,  with  pin  joints,  attached  to 
side  posts,  which  form  part  of  the  solid  framework  of  the  machine. 
To  the  lower  corner  of  the  rear  end  of  each  side  plate  is  fastened  a 
pin  and  roller  that  engages  with  a  cam  on  either  side  of  the  peel. 
After  the  box  has  been  filled  and  rammed,  it  is  placed  on  the 
pusher  platform  D  and  moved  to  the  oven.  When  the  oven  has 
been  emptied  and  the  coal  box  brought  into  position,  the  front 
door  of  the  box  is  opened  from  the  cab,  and  the  peel  set  in  motion. 
This  starts  the  peel  toward  the  oven,  pushing  forwards  on  the 
sides,  causing  them  to  rotate  about  their  several  points  of  support, 
thus  relieving  the  cake  of  coal  from  any  side  pressure.  The  coal 
is  then  placed  in  the  oven  on  the  peel  and  the  doors  closed.  The 
door  on  the  end  of  the  oven  nearest  the  coal  box  is  lowered  to  the 
peel  and  the  peel  withdrawn,  leaving  the  cake  of  compressed  coal 
in  the  oven.  The  cams  on  the  peel  on  their  return  engage  with 
the  pins  on  the  rear  end  of  the  side  plates,  and  draw  them  into 
their  original  position,  locking  them.  The  front  doors  are  then 
closed  and  the  coal  box  returned  to  the  ramming  station  for  a 
fresh  charge.  The  machine  is  mounted  on  heavy  trucks  that  are 
driven  by  a  50-horsepower  electric  motor,  which  also  operates  the 
peel.  By  means  of  these  trucks  and  motor,  the  box  is  run  under- 
neath the  bin  to  receive  its  charge,  or  back  on  to  the  platform  of 
the  coke  pusher.  The  box  is  held  on  the  pusher  by  rail  clamps 
operated  from  the  cab. 

Coke  Pusher. — The  two  coke  pushers  at  this  plant  are  operated 
as  follows:  The  coke  is  pushed  from  the  ovens  by  means  of  a 
heavy  ram  F,  Fig.  34,  carrying  a  cast-steel  rack  that  is  driven  by 
a  pinion,  connected  by  means  of  suitable  gearing  to  a  50-horse- 
power electric  motor.  This  ram  is  guided  by  means  of  rollers,  a 
sufficient  number  being  used  to  hold  it  properly  in  place.  On  the 
framework  of  this  machine  are  also  provided  tracks  for  a  coal- 
charging  box.  The  whole  mechanism  is  carried  on  a  massive  steel 
framework  D  resting  on  four  track  wheels  that  are  connected  by 
means  of  suitable  gearing  and  clutches  to  the  50-horsepower  motor 
used  to  operate  the  ram. 

Situated  on  this  steel  framework  in  a  convenient  position  is 
the  operator's  cab,  built  up  of  steel  framework  and  covered  with 
corrugated  galvanized  iron,  and  also  containing  a  sufficient  number 
of  windows  to  allow  the  operator  a  good  view  of  all  the  operations 
of  the  machine.  The  operator's  cab  contains  the  controllers,  etc. 
for  all  the  operations  of  this  machine,  which  are  as  follows:  The 
pusher  is  run  along  the  tracks  parallel  to  the  line  of  coke  ovens, 
until  the  tracks  on  the  pusher  platform  are  directly  opposite  those 


TREATISE  ON  COKE 


319 


from  the  coal  bin.  The  coal-charging  box  is  run  on  to  the  pusher 
platform  and  clamped  there  by  means  of  rail  clamps  on  the  coal  box. 
The  whole  machine  is  then  moved  to  a  position  in  front  of  the  oven 


to  be  drawn.  The  clutch  connecting  the  motor  with  the  pinion  dri- 
ving the  ram  is  engaged  and  the  coke  pushed  out  of  the  oven.  The 
coal-charging  box  is  then  placed  in  front  of  oven  as  described  above. 


320  TREATISE  ON  COKE 

For  carrying  the  boxes  underneath  the  bins  and  rammers, 
four  platforms  and  tracks  are  provided.  These  platforms  consist 
of  a  steel  framework  supported  on  columns  and  carrying  a  plate 
floor,  resting  on  beams,  and  also  two  lines  of  rails,  forming  tracks 
for  the  charging  boxes  to  pass  backwards  and  forwards  underneath 
the  rammers  when  the  coal  is  being  compacted.  The  platform 
has  a  factor  of  safety  of  six,  on  account  of  vibration  during  the 
process  of  compacting. 

Details  of  the  construction  of  the  coal-charging  box  and  coke 
pusher  are  shown  in  Fig.  35. 


PLANT  FOR  SAVING  COKE  BY-PRODUCTS* 

The  Extension  of  the  Coal- Distillation  Plant  at  the  Matthias 
Stinnes  Mine  in  Carnap,  Germany. — The  following  is  taken  from 
an  article  by  Doctor  Bertelsmann  appearing  in  the  Zeitschrift  fur 
Berg-Hiitten  und  Salinenwesen  for  1901,  page  481: 

At  the  Matthias  Stinnes  bituminous  coal  mines  there  have 
hitherto  been  but  thirty  coke  ovens;  these  were  of  the  under-fired 
type  and  were  arranged  to  recover  the  tar  and  ammonia  from  the 
gas,  which  was  used  exclusively  for  heating  the  ovens.  During 
the  4  years  in  which  they  have  been  in  operation,  a  series  of  tests 
were  carried  out  in  order  to  obtain  exact  data  on  the  following 
points:  (1)  how  to  obtain  the  best  coke  from  a  high  volatile 
bituminous  coal;  (2)  how  to  obtain  the  largest  amount  of  surplus 
gas  of  high  calorific  and  candlepower,  fit  for  illuminating  and 
power  purposes;  (3)  what  by-products  can  be  recovered  from  the 
gas,  in  what  quantities,  and  into  what  form  can  they  be  most 
profitably  worked  up. 

The  results  of  these  tests  afforded  the  data  in  accordance  with 
which  the  extension  of  the  existing  plant  was  laid  out.  They  were 
as  follows:  (1)  a  coal-mixing  plant;  (2)  thirty-five  coke  ovens, 
with  gas  producers,  reversing  gear  and  regenerators,  apparatus 
for  the  separation  of  the  coke-oven  gas,  also  pushing  and  charging 
machines  and  coal-compressing  apparatus;  (3)  condensing  plant 
for  washing  the  gas  and  recovering  the  by-products;  (4)  an 
ammonia  plant;  (5)  a  benzol  plant;  (6)  a  cyanide  plant;  (7)  an 
office  building,  with  eating  hall  and  bathrooms.  With  the  excep- 
tion of  the  cyanide  plant,  the  above  are  either  completed  or  in 
process  of  erection  and  will  be  hereafter  described.  A  description 
of  the  cyanide  plant  cannot  be  given,  as  the  details  are  as  yet 
undecided. 

Coal-Mixing  Plant. — The  coke  made  from  a  high  volatile  coal, 
in  consequence  of  its  coarse-grained  structure  and  the  large  amount 
of  the  evolved  gas,  is  very  porous,  brittle,  and  apt  to  be  full  of 
cracks  and  therefore  ill  adapted  to  stand  the  burden  in  the  blast 

*Mines  and  Minerals,  December,  1902,  page  214. 


TREATISE  ON  COKE  321 

furnace.  It  may  be  improved  by  crushing  the  coal  and  pressing 
it  into  a  solid  cake  before  charging  into  the  oven.  Tests  were  made 
to  ascertain  whether  a  mixture  of  different  coals  would  improve 
the  coke,  and  it  was  found  that,  with  the  addition  of  from  10  to 
20  per  cent,  (weicher  staubiger  Kohle)  lean,  dry  coal,  the  strength 
and  density  of  the  coke  were  notably  increased.  In  order  to  do 
this  on  a  large  scale,  the  coal-mixing  plant  was  installed.  The 
coking  coal,  coming  direct  from  the  mines  to  the  washer,  and 
drained  of  most  of  its  water  in  the  storage  bins,  is  brought  to  the 
plant  by  a  chain  conveyer,  while  the  outside  coal  is  brought  in 
by  rail  and  unloaded  by  hand.  The  two  kinds  of  coal  are  elevated 
to  separate  hoppers,  of  which  there  are  four,  placed  on  the  four 
corners  of  a  square.  Each  hopper  ends  in  a  conical  spout,  which 
is  provided  at  its  lower  end  with  a  loose  sleeve,  adjustable  verti- 
cally. Beneath  these  spouts  is  a  horizontal  mixing  table  that 
revolves  about  a  central  vertical  axis.  As  the  adjustable  sleeves 
are  raised,  a  certain  amount  of  the  coal  runs  out  of  the  spouts  on 
to  the  moving  table,  and  is  scraped  from  there  by  an  adjustable 
arm  into  a  mixing  screw.  The  proportion  of  each  coal  in  the 
mixture  is  controlled  by  the  adjustable  sleeve  and  scraping  arm. 
The  screw  discharges  to  a  disintegrator,  which  still  further  mixes 
and  crushes  the  coal,  and  it  is  then  elevated  to  two  large  coal 
hoppers  above  the  ovens.  Power  for  the  mixing  plant  is  furnished 
by  a  single-cylinder  steam  engine. 

Ovens. — As  already  stated,  it  was  desired  to  select  an  oven 
system  that  would  afford  the  largest  possible  amount  of  surplus 
gas,  this  gas  to  be  suitable  for  use  in  gas  engines  at  the  adjoining 
coal  mines.  For  this  reason  it  was  inevitable  that  a  return  should 
be  made  to  the  method  of  recovering  the  heat  of  the  chimney 
gases  by  means  of  the  regenerative  system.  The  newly  constructed 
ovens  are  thirty-five  in  number  and  of  the  double-wall  type  with 
vertical  flues,  each  flue  being  separately  heated,  and  connected  with 
the  other  flues  only  by  the  common  off-head  canal.  Canals  and 
pipes  laid  beneath  the  coke  platform  bring  the  heated  air  and  the 
gas  to  their  respective  canals,  lying  beneath  the  oven  floor  and 
the  heating  flues,  each  serving  for  the  two  oven  walls.  From  these 
canals  the  air  and  gas  are  admitted  to  each  separate  vertical  heat- 
ing flue.  As  insufficient  air  is  admitted,  only  a  partial  combustion 
ensues,  in  order  to  avoid  local  overheating,  complete  combustion 
taking  place  on  the  entrance  of  additional  air,  entering  at  a  point 
in  the  middle  of  each  heating  flue.  The  burned  gases  from  all  the 
flues  pass  to  a  common  horizontal  canal  above  and  descend  from 
this  through  three  vertical  off-head  flues  to  the  chimney  canal, 
on  the  pusher  side  of  the  ovens.  The  admission  of  the  primary 
and  secondary  air  and  the  gas  is  regulated  for  each  two  walls,  and 
the  draft  opening  to  the  chimney  canal  for  each  wall  by  dampers. 
The  heated  gases  from  all  the  ovens  pass  through  a  reversing 
valve  to  one  of  two  regenerators,  where  the  heat  is  absorbed  by 


322  TREATISE  ON  COKE 

checkerwork,  passing  thence  through  a  second  smaller  reversing 
apparatus  to  the  stack.  The  air  for  combustion  is  forced  through 
the  other  regenerator  in  the  reverse  direction  by  a  motor-driven  fan 
placed  at  the  small  reversing  valve,  is  heated  by  the  checkerwork, 
and  passes  through  the  large  reversing  valve  to  the  before-men- 
tioned air  canal.  At  the  end  of  each  reversal  period,  the  valves 
are  moved  120°  and  the  regenerators  interchange  their  functions. 
The  charging  of  the  coking  chamber  can  be  done  through  the 
customary  openings  above,  but  consists  usually  in  pushing  the 
cake  of  compressed  coal  into  the  oven  from  the  pusher  side.  For 
this  purpose  an  electrically  driven  charging  machine,  having  two 
stamping  boxes,  is  used.  Over  each  box  is  an  electrically  driven 
stamper.  The  coal  to  be  stamped  can  be  delivered  to  the  boxes 
at  any  point  along  the  battery  by  overhead  conveyers. 

Each  oven  is  provided  with  a  riser  pipe  in  the  middle  to  con- 
duct away  the  gas.  These  risers  connect  with  two  U-shaped 
mains,  and  are  on  each  side  for  the  rich  and  poor  gas  respectively. 
The  connection  to  these  mains  is  made  by  movable  valves  dipping 
into  a  seal  to  make  them  gas-tight.  The  rich  gas  is  given  off  only 
during  the  first  part  of  the  coking  time,  the  remainder  being 
classed  poor  gas.  Separate  pipes  take  the  two  gases  to  the  con- 
densing house,  there  being  a  tar  drain  from  each  to  a  common 
reservoir. 

Condensing  Plant. — In  accordance  with  the  plan  of  handling 
two  qualities  of  gas,  the  condensing  plant  consists  of  two  identical, 
but  entirely  distinct,  systems.  The  gases  coming  hot  from  the 
oven  pass  first  through  high  annular  air  coolers,  then  to  rectangu- 
lar water  coolers,  leaving  them  at  atmospheric  temperature. 
They  are  then  forced  by  exhausters  into  the  tar  scrubber,  then  to 
a  series  of  rotating  slat  washers,  one  after  the  other.  In  these, 
the  ammonia,  benzol,  and  cyanide  are  absorbed  by  suitable  liquids, 
the  sulphureted  hydrogen  being  removed  from  the  rich  gas  as 
well.  This  completes  the  washing  process,  the  gases  passing 
directly  to  where  they  are  used,  as  already  described.  The  air 
coolers,  as  has  been  stated,  are  annular  in  form,  that  is  to  say, 
having  an  inner  air-shaft  so  that  the  air-cooling  effect  takes  place 
from  both  sides  at  once.  All  the  coolers  are  divided  by  partition 
walls  so  that  the  inlets  and  outlets  are  at  the  bottom,  allowing 
several  coolers  to  be  connected  with  little  space  between,  thus 
avoiding  long  pipe  connections  and  one-sided  loads  on  the  cooler 
shells.  The  water-tube  coolers  are  so  arranged  that  the  gas  and 
water  pass  through  in  opposite  directions.  The  warm  water 
passes  under  its  own  pressure  to  an  open  cooler  of  wooden  lattice- 
work, when  it  is  cooled  by  evaporation,  and  is  raised  from  a  col- 
lecting basin  to  the  elevated  tank  over  the  water  coolers  by  rotary 
pumps,  to  be  used  again.  The  tar  and  ammoniacal  liquor  con- 
densed in  the  coolers  is  led  to  a  gravity  separating  tank  and  is 
carried  by  pumps  to  be  worked  up. 


TREATISE  ON  COKE  323 

Each  of  the  nine  rotating  slat  washers  consists  of  a  large  cast- 
iron  drum  having  an  outside  flange  near  each  end,  traveling  on 
two  pair  of  grooved  rollers,  which  drive  it  by  friction.  The  entrance 
and  exit  of  the  gas  is  through  stufhngboxes.  The  drum  is  divided 
by  thin  cast-iron  partitions  having  a  central  opening  into  four 
equal  chambers,  each  being  again  divided  by  a  wooden  partition, 
so  that  communication  is  along  the  periphery  only.  The  space  in 
the  chambers  is  then  filled  with  closely  fitting  gratings  of  wood. 
The  washing  liquid  enters  and  leaves  through  stuffingboxes  at 
either  end,  the  direction  of  its  passage  being  opposed  to  that  of 
the  gas.  The  upper  half  of  the  washer  is,  therefore,  always  filled 
with  gas  and  the  lower  part  with  wash  liquor,  both  moving  in 
opposite  directions,  and,  by  the  rotation  of  the  drum,  the  gas  is 
forced  to  pass  continually  over  freshly  wetted  and  dripping  surfaces, 
so  that  an  intimate  contact  between  gas  and  liquid  is  assured. 
No  gate  valves  are  employed  on  the  gas  mains  and  by-passes,  seal 
pots  with  dip  pipes  or  partitions  being  used,  which  can  be  made 
gas-tight  at  any  time  by  filling  with  water. 

The  motive  power  for  the  condensing  house  is  supplied  by 
two  single-cylinder  steam  engines  with  poppet  valves,  used  alter- 
nately. These  drive  the  apparatus  already  mentioned,  and,  in 
addition,  six  horizontal  piston  pumps  for  circulating  the  waste 
liquors,  a  gas  compressor,  and  two  dynamos  for  light  and  power 
purposes. 

Ammonia  Plant. — The  ammonia  is  removed  by  washing  the 
gas  with  water  after  it  has  been  freed  of  tar.  The  liquor  from  the 
washers  and  the  condensate  from  the  coolers  are  collected  in  one 
reservoir  and  raised  by  a  piston  pump  to  an  elevated  tank,  from 
which  the  mixture  flows  by  gravity  to  the  ammonia  house.  In 
order  to  obtain  ammonia  in  a  salable  form  it  must  first  of  all  be 
separated  from  the  liquor  and  to  some  extent  purified.  This 
process  may  be  divided  into  four  parts:  (a)  the  preheating  of 
the  liquor;  (6)  the  driving  off  of  the  carbonic  acid  and  the 
sulphureted  hydrogen;  (c)  the  driving  off  of  the  free  ammonia; 
(d)  the  driving  off  of  the  fixed  ammonia. 

(a)  The  preheating  of  the  liquor  is  done  in  an  apparatus  in 
which  a  part  of  the  water  that  has  given  up  its  free  ammonia  is 
used  to  heat  the  raw  ammonia  liquor.  The  apparatus  consists  of 
a  series  of  cast-iron  chambers  placed  one  above  the  other,  and 
divided  by  thin  steel  plates,  the  first,  third,  fifth,  etc.,  and  the 
second,  fourth,  sixth,  etc.,  being  connected,  so  that  two  entirely 
separate  circulation  systems  of  alternate  raw  liquor  and  hot  water 
are  formed.  The  flow  is  in  opposite  directions,  the  transmission  of 
heat  being  through  the  partitions. 

(6)  The  liquor,  thus  warmed,  passes  upwards  under  pressure 
and  flows  down  through  a  small  column.  In  this  it  encounters  a 
current  of  fresh  steam,  or  of  escaping  steam  from  the  apparatus 
below,  described  later,  which  in  either  case  is  sufficient  to  drive 


324  TREATISE  ON  COKE 

off  the  carbonic  acid  and  sulphureted  hydrogen,  but  not  the 
ammonia.  The  gases  so  driven  off  are  returned  to  the  unwashed 
oven  gas. 

(c)  The  partially  purified  water  now  comes  to  the  upper  por- 
tion  of   the   large   column   apparatus.     As   it   passes   downwards 
through  the  latter,  it  encounters  enough  steam  to  free  it  of  all  its 
volatile  ammonia.     A  part  of  the  heated  water  is  then  removed  to 
pass  through  the  before-mentioned  preheater,  to  warm  the  raw 
liquor,  and  after  serving  this  purpose  is  used   again  in  the  slat 
washer  for  condensing  purposes.     In  this  way  the  incrustation  of 
the  washer    slats    with  scale,   which    is    generally    the    result    of 
constantly  using  spring  or  river  water,  is  avoided. 

(d)  The  liquor  passing  down  through  the  column  enters  the 
lime  chamber  by  a  seal  pipe  and  is  then  mixed  with  milk  of  lime, 
forced  into  the  chamber  by  a  pump.     Passing  thence  to  the  lower 
part  of  the  column  it  encounters  fresh  steam  and  is  deprived  of 
the  ammonia  set  free  by  the  lime.     The  waste  liquor,  now  free  of 
ammonia,  is  allowed  to  settle  in  the  lime  tanks  and  runs  to  waste. 

The  ammonia  thus  obtained  in  gaseous  form  is  still  mixed  with 
a  good  deal  of  steam,  and  can  easily  be  transformed  into  ammonium 
sulphate  or  strong  ammonia  liquor,  as  desired.  The  manufacture 
of  aqua  and  liquefied  anhydrous  ammonia  is  also  contemplated. 

In  making  ammonium  sulphate,  elevated  lead-lined  wooden 
boxes,  reenforced  with  iron  and  set  above  the  floor,  are  used. 
The  arched  lid  is  of  cast  iron,  lead  covered,  and  carries  a  number 
of  lead-covered  connections  that  allow  ammonia  vapor,  acid,  and 
mother  liquor  to  be  introduced  and  the  waste  vapors  to  escape. 
The  ammonia  vapors  are  admitted  through  dip  pipes,  beneath 
circular  toothed  hoods,  allowing  an  intimate  contact  between 
vapor  and  liquid.  The  vapors  given  off  escape  through  one  of  the 
connections  to  a  condenser  overhead,  the  baffles  in  which  catch 
and  hold  any  entrained  liquid,  and  pass  thence  to  the  foul-gas 
main.  The  bottom  of  the  box  slopes  from  all  sides  toward  the 
middle  and  is  furnished  with  an  opening,  closed  by  a  hard-lead 
cone  worked  by  levers  from  the  outside.  Under  each  saturating 
box  is  a  lead-lined  receiver.  The  operation  is  as  follows :  Through 
one  of  the  connections  certain  quantities  of  60°  sulphuric  acid  and 
mother  liquor  from  the  last  operation  are  introduced  and  saturated 
by  the  passage  of  ammonia  gas.  When  the  saturation  is  complete, 
the  contents  of  the  box  are  run  into  the  vessel  below,  through  the 
opening,  and  then  allowed  to  settle.  The  clear  mother  liquor  is 
drawn  off  and  the  salt  is  dried  in  a  centrifugal  separator.  The 
latter  is  then  ready  for  market.  The  mother  liquor  is  drained  to 
a  collecting  basin  and  then  raised  by  a  hard-lead  injector  to  an 
overhead  tank,  from  which  it  flows  to  the  saturating  boxes  again. 
If  the  ammonia  vapor  is  to  be  worked  up  into  concentrated  liquor, 
it  is  deprived  of  a  certain  portion  of  its  water  in  a  return-flow 
condenser  and  then  entirely  cooled,  the  finally  condensed  strong 


TREATISE  ON  COKE  325 

liquor  being  drawn  off  and  marketed  in  that  form.  The  floor  and 
walls  of  the  ammonia  house  are  covered  with  asphalt,  so  as  to  resist 
the  action  of  the  acid  and  mother  liquor. 

Benzol  Plant. — The  benzol  and  its  homologues  are  absorbed 
from  the  gas  by  washing  it  with  dead  oil  in  one  of  the  rotary  slat 
washers  already  described,  the  saturated  oil  being  pumped  to  the 
benzol  plant.  Here  it  flows  first  through  preheaters,  like  those 
in  the  ammonia  works,  supplied  with  hot  dead  oil  from  the  other 
apparatus.  From  the  preheater  it  comes  to  the  column  apparatus, 
and  passing  downwards  through  this  is  exposed  to  the  action  of 
ascending  steam  and  is  deprived  of  its  benzol,  etc.  The  action  of 
the  steam  is  enhanced  by  arranging  the  columns  in  a  circle  about 
a  central  shaft,  from  which  they  are  all  directly  heated  by  gas. 
The  oil  leaving  the  column  serves,  as  already  stated,  to  preheat 
the  incoming  oil,  is  then  entirely  cooled  in  water  coolers,  and  passes 
again  to  the  gas  washer.  The  vapors  recovered  from  the  oil  in 
this  process  consist  of  water  and  benzol  hydrocarbons.  After  con- 
densing, they  are  separated  into  water  and  raw  benzol  and  the 
latter  collected  in  a  tank.  From  this  it  is  redistilled  by  means  of 
a  still  provided  with  column  and  returns  condenser,  so  operated, 
first  with  indirect  and  then  with  direct  steam  and  by  regulating 
the  condenser,  as  to  deliver  90-per-cent.  or  50-per-cent.  or  other 
degree  benzol,  as  desired.  The  separate  fractions  are  run  into 
separate  receivers  and  pass  thence  to  the  storage  reservoirs.  It  is 
also  intended  to  install  apparatus  for  rectification  with  sulphuric 
acid,  and  further  fractional  distillation. 


CHAPTER  VII 


PHYSICAL  PROPERTIES  OF  CHARCOAL,  ANTHRACITE,  AND 

COKE,  AND  A  COMPARISON  OF  BEEHIVE  AND 

BY-PRODUCT  COKE 

The  law  of  progress  is  universal.  Beginning  with  the  blade, 
then  the  ear,  and  ultimately  the  full  corn  in  the  ear.  The  iron 
manufacturers  have  studied,  under  many  years  of  practical  expe- 
rience, the  properties  and  values  of  the  principal  fuels  in  general 
use  for  iron  smelting — charcoal,  anthracite,  and  coke. 

The  following  table,  from  J.  M.  Swank's  "Iron  in  All  Ages," 
will  exhibit  in  a  very  interesting  way  the  struggle  of  these  fuels 
for  supremacy,  with  their  present  ranks,  the  coke  leading  all  others: 

TABLE  I 


Years 

Charcoal 
Net  Tons 

Anthracite 
and  Coke 

Coke 
Net  Tons 

Remarks 

Net  Tons 

1854 

342,298 

339,435 

54,485 

1855 

339,922 

381,866 

62,390 

Anthracite  leads  charcoal 

1869 

392,150 

971,150 

553,341 

Coke  leads  charcoal 

1875 

410,990 

908,046 

947,545 

Coke  leads  anthracite 

1880 

703,522 

2,448,781 

7,154,725 

Era  of  coke 

1900 

339,874 

1,636,366 

11,727,712 

Era  of  coke 

1901 

360,147 

1,668,808 

13,782,386 

Era  of  coke 

1902 

378,504 

1,096,040 

16,315,891 

Era  of  coke 

This  exhibit  establishes  the  fact  that  the  use  of  coke  in  smelt- 
ing iron  is  largely  on  the  increase,  and  that  the  use  of  anthracite 
is  decreasing,  especially  when  used  alone  in  blast  furnaces;  while 
charcoal,  in  its  limited  use,  appears  to  be  nearly  stationary. 

As  coke  is  now  the  chief  fuel  in  the  metallurgy  of  iron  and  steel, 
and  its  use  is  steadily  increasing,  it  is  evident  that  it  is  destined  to 
maintain  its  prominent  place  of  usefulness  in  the  coming  ages, 
increasing  in  largest  proportion  with  the  expansion  of  the  manu- 
facture of  iron  and  steel. 

The  table  also  shows  that  coke  has  superseded  anthracite  in 
blast-furnace  operations.  Where  the  relative  cost  of  coke  to 

326 


TREATISE  ON  COKE 


327 


anthracite  does  not  largely  exceed  25  to  30  per  cent.,  the  former 
fuel  would  probably  obtain  the  preference,  from  its  greater  calorific 
energy  in  the  production  of  a  larger  output  of  pig  iron  in  the 
furnace. 

At  present,  furnaces  within  the  borders  of  the  economic  bounds 
of  coke  are  using  this  fuel  mainly  and  obtaining  supplies  from 
the  Connellsville,  Alleghany,  and  Clearfield  regions. 

Mixtures  of  coke  with  anthracite  are  made  at  some  furnaces, 
ranging  from  one-eighth  to  one-half  of  the  fuel  charge.  It  is 
evident,  however,  that  the  use  of  coke  in  blast  furnaces  is  steadily 
on  the  increase  and  will  continue  to  enlarge  the  bounds  of  its 
usefulness,  displacing  the  less  energetic  anthracite  fuel. 

From  the  limited  area  of  the  chief  anthracite  fields  in  the  East, 
containing  in  the  aggregate  only  488  square  miles  of  coal  measures, 
and  from  its  present  large  annual  output  of  53,967,543  net  tons 
in  1893,  with  a  deeper  and  increasing  cost  of  mining,  it  cannot 
long  profitably  continue  to  supply  furnace  fuel  at  very  low  rates. 

The  charcoal  fuel  for  blast-furnace  use,  under  the  rapid  cutting 
down  of  the  primeval  forests,  must  continue  to  afford  only  a  lim- 
ited supply  and  its  use  be  confined  to  the  smelting  of  pig  metal 
for  special  purposes. 

From  all  the  foregoing  it  will  be  seen  that  the  present  and 
future  manufacture  of  coke  demands  and  should  receive  increased 
and  earnest  attention. 

The  following  table  exhibits  the  decrease  and  increase  of  the 
use  of  the  fuels  used  in  blast-furnace  operations,  in  detail:* 

TABLE  II 


Fuel  Used 
Gross  Tons 

1898 

1899 

1900 

1901 

1902 

Bituminous, 

chiefly  coke 

10,273,911 

11,736,385 

11,727,712 

13,782,386 

16,315,891 

Anthracite 

and  coke  .  . 
Anthracite 

1,180,999 

1,558,521 

1,636,366 

1,668,808 

1,096,040 

alone  

22,274 

41,031 

40,682 

43,719 

19,207 

Charcoal.  .  .  . 
Charcoal  and 

296,750 

284,766 

339,874 

360,147 

378,504 

coke  

44,608 

23,294 

11,665 

Totals.... 

11,773,934 

13,620,703 

13,789,242 

15,878,354 

17,821,307 

This  table  shows  in  a  very  emphatic  manner  that  coke  is  the 
principal  fuel  now  in  use  in  blast-furnace  and  other  metallurgical 
operations,  and  that  anthracite  alone  holds  a  small  and  vanishing 
place  in  these  great  industries. 

*From  statistical  tables  by  James  M.  Swank,  general  manager 
American  Iron  and  Steel  Association,  1903. 


328 


TREATISE  ON  COKE 


Charcoal,  in  use  mainly  for  special  purposes,  maintains  its 
small  place  among  these  fuels. 

In  these  fuels,  especially  for  blast-furnace  and  kindred  uses, 
the  prime  requisites  are  hardness  of  body,  to  sustain  the  weight 
of  furnace  charges,  to  resist  dissolution  in  the  upper  portion  of  the 
furnace,  and  full  cellular  structure  to  afford  combustion  with  the 
utmost  energy  at  the  proper  zone  in  the  furnace.  These  elements 
in  the  fuels  are  essential  in  the  economical  and  vigorous  working 
of  the  furnace. 

Charcoal  was,  in  the  early  times  of  iron  making,  the  principal, 
if  not  the  only  fuel  used  in  forges  and  blast  furnaces.  From  its 
softness  of  body  it  could  only  be  used  in  the  old-time  forges  and 
low  furnaces  with  feeble  blast  in  the  initial  operations  of  iron 
smelting.  It  was  the  educating  fuel  in  the  early  operations  of 
iron  smelting  and  iron  working. 

Anthracite  is  a  natural  coke.  From  its  hardness  of  body  it 
is  abundantly  able  to  sustain  the  pressure  of  the  highest  furnace 
charges,  as  well  as  to  resist  the  dissolving  action  of  hot  carbon- 
dioxide  gas,  but  its  extreme  density  of  physical  structure  renders 
its  combustion  slow,  and  its  calorific  energy  moderate. 

Between  these  extremes  of  blast-furnace  fuels,  coke  comes  to 
the  iron  manufacturer  inheriting  in  harmonious  combination  the 
good  properties  of  charcoal  and  anthracite.  It  has  hardness  of 
body  to  sustain  the  burden  of  the  highest  furnace,  and  this  hard- 
ness enables  it  to  resist  dissolution  in  its  passage  down  the  furnace 
to  the  zone  of  combustion.  Its  large  surface  space  from  its  cellu- 
lar structure  affords  full  preparation  before  reaching  the  zone  of 
fusion,  which  assures  great  calorific  energy  in  its  combustion. 

Beginning  with  1850,  the  three  fuels  at  the  service  of  the  iron 
manufacturer  consisted  of  wood  charcoal,  anthracite,  and  coke. 
These  are  composed  as  follows: 

TABLE  III 


Fuel 

Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Charcoal  

3.50 

6.490 

87.00 

3.00 

020 

Anthracite 

2  50 

4  000 

87  00 

6  00 

50 

020 

Coke  .  . 

.49 

Oil 

87  46 

11  32 

69 

029 

It  required  time  to  assure  furnace  managers  of  the  special  fuel 
best  adapted  for  their  use,  considering  cost,  energy  of  fuel,  and 
quality  of  pig  iron  made. 

During  the  past  two  decades  the  examination  of  furnace  fuels 
embraced  not  only  their  chemical  constituents,  but  also  their  phys- 
ical properties.  This  has  led  to  the  conclusion  that  the  physical 
structure  is  a  very  important  factor  in  conferring  energy  in  the 


TREATISE  ON  COKE  329 

combustion  of  the  fuel.  Rapid  combustion  in  the  furnace  results 
in  increased  output  with  corresponding  reduction  of  cost  of  pig  iron. 

This  intelligent  study  of  the  physical  as  well  as  the  chemical 
properties  of  these  fuels  in  furnace  use  did  not  end  here;  but  the 
correlated  study  of  the  form  and  size  of  the  furnace,  the  heat  and 
pressure  of  blast,  have  been  put  into  successful-  practice  in  the 
smelting  of  iron.  This  has  led  to  the  development  of  the  fuel  best 
adapted  to  these  metallurgical  operations,  especially  in  the  large 
blast  furnaces  for  the  production  of  Bessemer  pig  iron. 

It  becomes,  therefore,  most  important  to  the  coke  manufac- 
turer to  consider  the  essential  elements  in  coke  that  have  con- 
ferred on  it  the  most  distinguished  place  in  the  iron  industry,  so 
as  to  maintain  in  its  manufacture  these  desirable  properties.  If 
the  physical  structure  of  these  fuels  is  examined,  it  will  be  found 
that  charcoal  consists  of  a  series  of  longitudinal  tubes,  uniting 
with  each  other  and  affording  ready  passage  to  the  furnace  gases. 
The  walls  of  these  tubes  are  readily  oxidized.  Charcoal  is,  there- 
fore, a  pure  and  moderately  energetic  furnace  fuel. 

Anthracite  is  a  natural  coke,  made  under  immense  pressure, 
and  very  dense  in  its  physical  structure.  It  inherits  no  cellular 
structure,  as  it  has  been  fused  into  a  dense  vitreous  mass  by  the 
pressure  and  heat  under  which  it  was  made,  this  great  pressure 
repressing  the  cell  development.  It  is,  from  its  physical  structure, 
the  least  energetic  of  the  fuels  under  consideration.  Its  action  in 
a  blast  furnace  is  somewhat  relieved,  as  under  heat  it  decrepitates, 
and  thus  increases  the  extent  of  surfaces  exposed  to  the  oxidizing 
gases  of  the  furnace,  compensating  in  a  measure  for  its  density. 

Coke,  on  the  other  side,  has  a  structure  made  of  a  series  of 
irregular,  promiscuously  disposed  cells,  with  vitreous  walls;  these 
cells  are  connected  by  diminutive  passages  that  afford  free  courses 
for  the  oxidizing  gases  of  the  blast  furnace.  It  is  these  hard  vit- 
reous cell  walls  in  coke  that  give  it  the  superior  value  as  an  energetic 
fuel  in  blast  furnaces. 

From  the  foregoing,  it  will  be  evident  that  the  physical  struc- 
ture of  coke,  other  things  being  equal,  is  the  main  element  that 
confers  on  it  the  superior  place  it  holds  among  blast-furnace  fuels. 
The  same  is  true,  in  a  modified  way,  of  charcoal  fuel.  The  anthra- 
cite holds  the  lowest  rank. 

The  factor  of  the  cost  of  these  fuels  is  also  an  important  element 
in  determining  their  use  in  each  locality.  This,  however,  does  not 
enter  into  the  present  investigation,  except  as  a  qualifying  clause. 


PROPERTIES  OF  COKE 

The  main  inquiry  at  this  place  is  to  determine  the  nature  of 
the  physical  and  chemical  properties  that  are  most  desirable  in 
coke  for  blast-furnace  use,  and  to  meet,  as  far  as  possible,  these 
requirements  in  the  manufacture  of  coke.  These  requirements  in 


330 


TREATISE  ON  COKE 


coke  fuel  are  clearly  defined  under  five  distinct  elements  in  its 
manufacture:  hardness  of  body;  fully  developed  cell  structure; 
purity;  uniform  quality  of  coke;  and  coherence  in  handling. 

In  the  further  consideration  of  these  valuable  properties  in 
metallurgical  coke,  it  may  be  helpful  to  the -manufacturer  to  con- 
sider these  five  essentials  in  detail. 

Hardness  of  Body. — The  best  cokes  possess  a  hardness  of  body 
of  2  to  3  per  cent.  .  By  this  is  meant  hardness  of  body  or  cell 
walls,  not  density,  for  dense  cokes  are  usually  soft  or  punky; 
while  hard-bodied  cokes  are  generally  well  developed  in  cellular 
structure.  These  two  physical  properties,  hardness  of  body  of 
coke  and  full  cell  spaces,  are  correlated,  just  as  softness  of  body 
and  density  are  associated. 

The  coal  from  which  soft  coke  is  made  lacks  the  element  that 
fuses  and  hardens  and  is  therefore  deficient  in  these  prime  essen- 
tial qualities.  The  nature  of  this  fusing  element  or  elements  in 
coking  coals  has  not  been  clearly  defined,  at  least  such  information 
has  not  come  under  the  notice  of  the  writer. 

The  following  table  of  careful  tests  of  hardness  of  body  and 
development  of  cells  will  prove  interesting: 

TABLE  IV 


Locality 

Grams 
in  1  Cubic 
Inch 

Pounds 
in  1  Cubic 
Foot 

Percentage 
by 
Volume 

V  Compressive  Strength  I 
§  Per  Cubic  Inch, 
3  One-Fourth  Ultimate 
£•  Strength 

ITJ  Height  of  Furnace 
g  Charge,  Supported 
«*  Without  Crushing 

«H 
rt 

CJ. 

6 

Hardness 
Per  Cent. 

! 

Dry 

Wet 

Dry 

Wet 

Coke 

.Cells 

Standard  Coke 
Connellsville  

12.14 
15.02 
13.02 

21.34 
23.41 
22.41 

46.30 
57.20 
49.03 

81.25 
89.20 
85.37 

43.73 
47.68 
41.82 

56.27 
52.32 
58.18 

236 
340 
246 

94 
136 
97 

i 
i 
i 

3.0 
2.6 
2.3 

1.69 
1.91 
1.90 

Syracuse,  New  York  .. 
Morris  Run,  Pa  

NOTE. — The  Connellsville  coal  was  coked  in  beehive  ovens.  Morris  Run 
coal,  Tioga  County,  Pennsylvania,  was  coked  in  Semet-Solvay  ovens,  at 
Syracuse,  New  York,  and  the  same  quality  of  Morris  Run  coal  was  coked 
in  beehive  coke  ovens  near  the  mines. 

In  the  treatment  of  dry  coals,  the  hardness  of  the  body  of  the 
coke  can  be  increased  by  coking  such  coal  in  the  narrow  or  retort 
coke  ovens.  The  cell  structure  in  this  kind  of  oven  is  always 
more  or  less  depressed  as  compared  with  the  full  cellular  develop- 
ment in  coke  made  in  the  beehive  class  of  oven. 

In  any  type  of  oven,  maximum  heat  is  required  to  produce 
the  hardest-bodied  coke,  but  it  is  not  conducive  to  the  largest 
output  of  by-products. 


TREATISE  ON  COKE  331 

The  solution  of  this  question,  the  elements  in  coal  that  con- 
tribute to  its  fusion  in  a  coke  oven  and  assure  hardness  of  body 
with  large  cell  spaces,  is  most  important;  for,  if  they  were  known, 
equivalent  elements  could  be  supplied  to  coals  deficient  in 
them,  thus  improving  the  quality  of  coke  in  its  most  essential 
requirements. 

This  prime  necessity  of  hardness  of  the  body  of  coke  will  be 
evident  when  the  conditions  of  its  combustion  in  a  blast  furnace 
are  considered.  In  its  movement  down  the  furnace  to  a  short 
distance  above  the  tuyeres,  it  is  enveloped  in  the  ascending  cur- 
rents of  hot  gases,  mainly  carbon  dioxide;  this  gas  possesses  the 
power  of  dissolving  carbon  or  coke,  and  is  especially  destructive 
to  the  soft  variety. 

Sir  I.  Lowthian  Bell,  in  his  treatise  on  the  "Manufacture  of 
Iron  and  Steel,"  page  287,  gives  the  following: 

Hard  coke,  soft  coke,  and  charcoal  pounded  as  nearly  as 
possible  to  the  same  size  were  placed  in  a  hard-glass  tube,  which 
they  filled,  and  were  then  raised  to  a  good',  red  heat  in  a  Hoff- 
man double  furnace.  During  the  space  of  30  minutes,  800  cubic 
centimeters  of  carefully  dried  carbonic  acid  was  passed  over 
each  specimen.  The  issuing  gases  had  the  following  volumetric 
composition : 

HARD  COKE  SOFT  COKE  CHARCOAL 

PER  CENT.  PER  CENT.  PER  CENT. 

Carbonic  acid 94.56  69.81  35.20 

Carbonic  oxide 5 . 44  30 . 1 9  64 . 80 


100.00  100.00  100.00 

It  will  thus  be  evident  that  every  pound  of  coke  dissolved  by 
this  gas,  before  reaching  the  efficient  zone  of  combustion,  is  a 
double  loss,  reducing  the  heat  of  the  furnace  and  disarranging  its 
regular  operations. 

It  is  evident  that  an  equal  amount  of  fixed  carbon  in  these 
three  principal  fuels,  used  in  blast-furnace  operations,  will  afford 
equal  volumes  in  heat  units;  but  it  is  also  evident  that  the  time 
required  to  produce  these  heat  units  will  be  in  proportion  to  the 
extent  of  surface  exposed  to  the  oxidation  gases  in  the  blast 
furnace  or  similar  heating  operations.  A  pertinent  example  has 
been  witnessed  in  the  old-time  "back-log."  It  contained  a  cer- 
tain number  of  heat  units,  but  they  came  out  very  slowly.  It 
was  mainly  designed  to  "hold  fire,"  but  when  energetic  heat  was 
required  the  log  had  to  be  split  into  small  pieces  to  afford  a  greatly 
enlarged  surface  to  the  oxidation  agency  in  its  combustion.  This 
foundation  principle  holds  practically  true  in  the  combustion  of 
these  fuels,  the  anthracite  representing  the  "back  log";  the  char- 
coal and  coke,  the  rapid-burning  fire  in  front  of  the  "back  log." 

It  follows,  therefore,  that  in  all  coking  operations  any  element 
in  the  plan  of  the  chamber  of  the  oven  that  restrains  the  liberty 


332 


TREATISE  ON  COKE 


of  the  coal  in  its  fusing  to  make  fully  developed  cells,  reduces  in 
such  proportion  the  energy  of  the  fuel;  in  other  words,  every 
approach  to  the  dense  anthracite  structure  is  inimical  to  the  value 
of  the  fuel  for  rapid  and  energetic  combustion.  This  principle, 
not  generally  well  developed,  is  one  of  the  chief  elements  that  has 
held  the  product  of  the  round  or  beehive  coke  oven  in  such  accept- 
ance with  blast-furnace  managers,  and  enabled  it  to  maintain  its 
place  of  usefulness  in  the  presence  of  criticism  and  sarcasm  as  to 
its  wastefulness  and  antiquated  condition. 

It  will  be  seen  from  the  tabulated  statements  that,  at  the  close 
of  the  year  1902,  there  were  69,069  beehive  coke  ovens  in  operation 
in  the  United  States,  against  1,663  retort  ovens  of  all  forms. 

Well-Developed  Cell  Structure.— The  coals  best  adapted  for 
coke  making  will  usually  afford,  in  conjunction,  ample  cellular 
development  and  hardness  of  body.  The  value  of  full  cell  struc- 
ture in  coke  will  be  readily  appreciated  when  it  is  considered  that 
such  fuel  presents  the  largest  surface  for  pxidation  in  a  blast  fur- 
nace. The  desirable  ratio  of  cellular  space  to  the  cell  walls  or 
body  of  the  coke  has  been  carefully  determined,  and  found  to  be 
as  44  to  56,  nearly.  That  is,  the  cubic  contents  of  coke  body  to 
cell  space  is  as  43.73  per  cent,  of  coke  to  56.27  per  cent,  of  cells. 

The  evidence,  by  filling  these  cell  spaces  with  water  under  the 
receiver  of  an  air  pump,  clearly  shows  the  thorough  connections 
by  passages  of  all  the  cells  in  the  coke.  The  calorific  energy  of 
the  coke  fuel  in  the  crucible  of  a  blast  furnace  also  shows  how  easily 
and  thoroughly  the  blast  penetrates  these  cell  spaces  and  main- 
tains rapid  combustion. 

TABLE  V 


Grams  in 
1  Cubic 
Inch 

Pounds  in 
1  Cubic 
Foot 

Percentage 
by  Volume 

2  Strength 
c  Inch, 
Ultimate 
gth 

Furnace 
ipported 
Crushing 

w. 

rt 

M     4* 

t 

Locality 

•a-St  £ 

IT0-? 

O  o 

-§0 

0 

I 

&&" 

•5&! 

<u 

W  & 

'o 

Dry 

Wet 

Dry 

Wet 

Coke 

Cells 

go,  i 
8  o 

£& 

0 

1 

Pounds 

Feet 

Standard  Coke 

(a)  Connellsville  

12.51 

21.62 

47.69 

82.20 

43.93 

56.07 

301 

110 

1 

3.0 

1.74 

(b)  Otto-Hoffman  oven 

14.64 

21.02 

55.79 

80.07 

61.13 

38.87 

465 

186 

1 

3.1 

1   80 

(c)  Otto-Hoffman  oven 

20.49 

24.23 

78.07 

92.30 

77.22 

22.78 

940 

376 

1 

3.5 

1.82 

NOTE. — (a)  Coke  made  from  Connellsville  coal  in  beehive  ovens; 
(b)  coke  from  sides  of  Otto-Hoffman  oven,  from  Connellsville  coal ;  (c)  coke 
from  bottom  of  Otto-Hoffman  oven,  from  Connellsville  coal. 

It  is  impossible,  however,  to  make  good  coke  from  coal  that 
is  wanting  in  the  elements  that  assure  thorough  fusion  in  the 
coke  oven.  Inferior  coking  coals  can  be  coked  by  special  oven 


TREATISE  ON  COKE  333 

treatment,  but  the  coke  from  such  coal  is  always  of  a  lower 
quality.  No  condition  of  oven  treatment  can  make  good  coke 
from  bad  coking  coal. 

Table  V  exhibits,  in  a  marked  manner,  the  repression  of  cell 
development  when  Connellsville  coal  has  been  coked  in  Otto- 
HofTman  retort  coke  ovens,  as  compared  with  the  structure  of 
coke  made  from  same  quality  of  Connellsville  coal  and  coked  in 
the  modern  beehive  coke  oven. 

In  the  presence  of  these  facts,  in  regard  to  the  repression  of 
cell  development  in  retort  coke  ovens,  it  becomes  a  matter  of 
great  interest  to  determine  whether  the  increased  hardness  of  body 
of  the  retort-oven  coke  will  compensate  in  blast-furnace  work  for 
the  greatly  diminished  cell  space  in  this  coke.  It  will  require 
furnace  determinations  to  adjust  the  relative  loss  and  gain  from 
these  related  physical  conditions. 

Purity. — Carbon  is  the  source  of  heat  in  coke.  Other  proper- 
ties being  equal,  the  larger  the  percentage  of  carbon  the  greater 
is  the  volume  of  heat.  . 

As  coal  has  had  its  genesis  in  vegetable  matter,  it  usually  inherits 
3  per  cent,  to  7  per  cent,  of  ash.  A  coke,  therefore,  not  greatly 
exceeding  10  per  cent  of  ash  can  be  regarded  as  an  average  clean 
fuel.  Cokes  inheriting  only  5  per  cent,  to  7  per  cent,  of  ash  are 
regarded  as  exceptionally  pure. 

The  sulphur  in  coke  should  be  under  1  per  cent.,  if  the  fuel  is 
to  be  used  in  metallurgical  operations.  The  best  coke  contains 
only  i  to  f  per  cent,  of  this  impurity.  Ordinarily,  the  volume  of 
sulphur  in  coal  is  in  a  certain  proportion  to  its  slate  or  ash,  but 
there  are  exceptions  to  this  relationship  where  coal  high  in  ash  is 
quite  low  in  sulphur.  The  reduction  of  the  slate  in  coal  by  wash- 
ing or  picking  generally  reduces  the  percentage  of  sulphur.  About 
40  per  cent,  of  it  is  volatilized  in  the  coke  oven. 

A  reference  to  Chapter  III  will  show  the  great  progress  that 
has  been  accomplished  in  the  last  decade  in  cleaning  coal  from  its 
impurities  by  crushing,  classifying,  and  washing.  The  manufac- 
turer of  coke  has  now  all  kinds  of  washers  at  his  service,  so  that 
no  valid  excuse  can  be  urged  to  cover  the  production  of  impure 
coke.  But  it  may  be  submitted  here  that,  while  most  coking  coals 
can  be  successfully  treated  in  washeries,  yet  there  are  some  that 
cannot  be  cleaned  by  the  best  modern  appliances.  The  excep- 
tions, however,  are  so  limited  that  the  coke  manufacturer  need 
not  hesitate  to  submit  samplings  of  his  coal  for  washing  tests  to 
the  reliable  firms,  before  noted,  for  definite  determinations  in  the 
capability  of  the  washing  process  in  removing  slate,  sulphur,  and 
other  impurities  from  the  coal. 

Phosphorus  is  found  present  in  coke.  In  the  purest  varieties 
it  runs  from  .012  per  cent,  to  .029  per  cent.  As  a  general  expe- 
rience, the  phosphorus  in  the  coal  goes  over  to  the  coke;  but  there 


334  TREATISE  ON  COKE 

are  occasional  exceptions  to  this.  When  coal  is  washed  prepara- 
tory to  coking,  some  of  the  phosphorus  goes  out  in  the  slates  and 
refuse. 

Uniform  Quality  of  Coke.— The  uniform  quality  of  the  coke  is 
one  of  the  important  requirements  in  view  of  what  has  been  noted 
of  the  destructive  action  of  hot  carbon-dioxide  gas  on  the  soft 
portions  of  the  coke. 

The  black  ends  that  are  sometimes  made  in  coking  have  to  be 
included  in  weighing  charges  for  the  blast  furnace,  and  their  ready 
dissolution  reduces  the  heat  power  in  the  proper  zone  in  the  fur- 
nace. As  this  defect  can  be  controlled  by  the  manufacturer  of 
coke,  no  reasonable  defence  can  be  urged  for  the  presence  of  black 
ends  in  coke  made  for  furnace  use. 

It  has  been  shown  that  the  use  of  coke  as  a  metallurgical  fuel 
is  not  only  quite  large,  but  increasing  in  the  manufacture  of  iron 
and  steel.  The  large  number  of  establishments  for  the  manufac- 
ture of  coke  in  the  United  States  assure  the  truth  of  the  foregoing 
statement. 

Table  VI  will  show  the  physical  as  well  as  the  chemical  prop- 
erties of  American  and  Mexican  cokes.  In  examining  this  table 
it  will  readily  appear  that  in  the  best  coke  the  aggregate  of  cell 
space  to  body  of  coke  is  in  the  relation  of  44  to  56,  nearly.  It  is 
not  submitted  that  all  coking  coals  can  be  made  to  assure  this 
ratio  of  cells  to  body  of  coke,  but  in  the  coals  best  adapted 
for  making  good  coke,  a  close  approximation  to  these  physical 
relations  should  be  found. 

Coherence  in  Handling. — In  blast-furnace  practice,  it  has 
recently  been  determined  that  cokes  vary  widely  in  breakage  in 
handling  in  the  railroad  cars  and  at  the  furnace,  making  breeze 
that  is  undesirable,  and  which,  if  in  large  proportion,  congests  the 
furnace,  reducing  the  output.  This  fine  material  from  brittle  coke 
is  generally  thrown  aside  as  worthless.  In  careful  tests  recently 
made  of  three  principal  qualities  of  blast-furnace  cokes,  which  can 
be  designated  as  A,  B,  and  C,  5  tons  of  average  shipments  of  each 
variety  were  taken  just  as  received  in  railroad  cars  at  the  furnace ; 
these  classes  were  carefully  separated  into  large,  medium,  and  breeze. 
All  these  tests  were  made  by  volume,  with  the  following  results: 

ABC 
PER  CENT.      PER  CENT.     PER  CENT. 

Large  coke...  45.71  56.81  54.40 

Medium  coke 25.71  40.90  44.00 

Breeze 28.58  2.29  1.60 

From  the  above,  the  great  loss  in  fuel  and  freight  in  the  breeze 
produced  from  the  class  A  will  readily  appear.  The  cokes  B 
and  C  vary  little  in  the  loss  from  breeze.  But  the  medium  coke 
in  the  class  A,  from  its  brittle  property,  would  reduce  its  value  in 


eo.te 


TAX 

FULTON'S  TABLE  EXHIBITING  THE  PHYS 

REVIS] 


Locality 

Grams 
in  1  Cubic 
Inch 

Pounds 
in  1  Cubic 
Foot 

Percentage 
by  Volume 

Compressive  Strength 
Lb.  Per  Cubic  Inch, 
1  Ultimate  Strength 

Ft.  Height  of  Furnace 
Charge,  Supported 
Without  Crushing 

Order  in  Cellular 

Dry 

Wet 

Dry 

Wet 

Coke 

Cells 

Connellsville  —  Standard  Coke  .  . 

15.47 

23.67 

59.09 

90.28 

52.78 

47.22 

301 

149 
209 
316 
181 
245 
212 
213 
170 

•  933 

192 
409 
274 
227 
381 
327 
306 
245 
326 
236 
200 
90 
158 
146 
231 
340 
246 

804 
217 
240 
316 
280 
300 
431 
213 
216 
250 
274 
286 

296 
300 

120 

1 
I 

1 
1 

1 
1 
1 

1 

1 

1 
1 

1 
1 
1 
1 

1 

1 

Caledonia  Pa 

12.10 
13.57 
13.77 
12.44 
12.38 
10.89 
11.91 
13.39 

23.35 

12.34 
14.32 
13.31 
14.10 
14.16 
14.28 
12  .  63 
11.89 
12.20 
15.67 
11.64 
10.22 
9.78 
12.04 
12.90 
15.02 
15.02 

17.34 
12.49 
10.24 
12.04 
12.50 
12.93 
14.88 
11.90 
11.91 
14.11 
13.30 
12.25 

12.45 
12.42 

21.80 
22.41 
22.58 
22.17 
22.05 
20.98 
21.99 
20.61 

27.48 

22.19 
22.52 
19.90 
22.24 
22.93 
22.82 
22.05 
21.18 
21.02 
23  .  53 
21.87 
21.29 
20.69 
22.09 
22.27 
23.41 
22.41 

25.01 
21.46 
20.92 
21.92 
22.18 
22.64 
22.31 
22.00 
21.99 
22.25 
20.00 
21.20 

22.18 
22.19 

46.12 
51.69 
52.61 
47.39 
46.59 
41.49 
45.37 
51.02 

88.94 

50.94 
54.56 
50.71 
53  .  73 
53.88 
54.39 
48.11 
45.31 
46.49 
59.68 
44  .  35 
38  .  92 
37.89 
45.88 
49.16 
57.20 
49.03 

66.45 
47.60 
39.02 
45.87 
47.95 
49.28 
56.68 
45  .  32 
45.37 
53  .  72 
50.70 
46  .  50 

47.38 
47.35 

83.07 
85.38 
86.01 
84.48 
84.02 
79.94 
83.79 
78.54 

104.68 

86.37 
85.80 
75.82 
84.73 
87.33 
86.95 
84.02 
80.70 
80.09 
89.64 
83.32 
81.12 
78.85 
84.18 
84.86 
89.20 
85.37 

95.59 
81.75 
79.72 
83.50 
84.18 
86.25 
85.00 
83.84 
83.79 
84.74 
75.83 
80.10 

84.49 
84.52 

40.83 
46.07 
46.25 
40.63 
41.05 
38.43 
38.49 
55.95 

78.80 

39.93 

49.97 
59.80 
50  .  37 
46.48 
47.87 
42.33 
43.34 
46.22 
52.07 
37.61 
32.43 
34.41 
38.67 
42.76 
47.68 
41.82 

53  .  73 
45.31 
34.84 
39.76 
41.40 
40.79 
50.39 
38  .  45 
38.49 
50.40 
59.90 
42.22 

42.68 
40.60 

59.17 
53.93 
53.75 
59.37 
58.95 
61.57 
61.51 
44.05 

25.20 

60.07 
50.03 
40.20 
49.63 
53.52 
52.13 
57.67 
56.66 
53.78 
47.93 
62.39 
67.57 
65.59 
61.33 
57.24 
52.32 
58.18 
100.00 
46.67 
54.69 
65.16 
60.24 
58.60 
59.21 
49.61 
61.55 
61.51 
49.60 
40.10 
57.78 

57.32 
59.40 

60 
84 
126 
73 
98 
85 
85 
68 

373 

77 
164 
109 
91 
151 
131 
122 
98 
131 
94 
80 
36 
63 
58 
92 
136 
97 
100 
322 
87 
96 
126 
115 
120 
172 
85 
90 
103 
110 
113 

118 
119 

Caledonia,  Pa  
Walston   Pa  .            .        . 

Richland,  Pa  
Bennin°rton   Pa 

Gallitzin,  Pa  
Lilly   Pa 

Indian  Creek,  Pa  

Coosa  Ala    . 

Blocton,  Ala  
Pineville   Ky 

Pineville,  Ky  

Powelton  W.  Va  .  . 

Montana,  W.  Va  

Monongah,  W.  Va  
Big  Stone  Gap   Va 

Big  Stone  Gap,  Va  
Pocahontas,  Va  
Salville,  Va  
Lonaconing,  Md  

Hondo,  Mex 

Alamo,  Mex.  .  . 
Cardiff,  Wales.  .      .  . 

Syracuse,  N.  Y  

Morris  Run,  Pa  

Anthracite,  Pa. 

Glassport   Pa 

Indian  Territory  
Graceton,  Indiana  Co.,  Pa  
Jameson  Coal  &  Coke  Co  
Pinnickmnick,  W   Va 

Coal  City,  Ala  
Cumberland,  Tenn  
Marvtown,  W   Va 

Alleghany  coke  
Kentucky  coke  .  .  . 

Kentucky  coke  
West  Virginia  coke  
Kanawha  &  Hocking  Vallevl 
Coal  &  Coke  Co  /  • 
Great  Kanawha  Colliery  Co  

NOTE.— Chemical  analyses  by  T.  T.  Morrell,  Prof.  Andrew  S.  McCreath,  Doctor  Rothberg,  Hugo  C 


17303— vii 


VI 

:  AND  CHEMICAL  PROPERTIES  OF  COKE 


1 

Chemical  Analysis 

Per  Cent. 

c§       <§ 

i       *    f  ,     •> 

in 

Remarks 

<D                   D 

t-i 

ft 

1 

B    ll 

1|       $ 

I 

O 

H 

C/2 

0  *rH 

,^d 

1 

0 

.0 

1.80 

.42 

.80 

87.46 

11.32 

.69 

.015 

Average  Standard 

.0 

1.80 

.130 

.990 

87.890 

9.420 

1.570 

.0240 

Beehive  oven,  48  hours 

.0 

1.81 

Beehive  oven,  72  hours 

.0 

1.82 

.310 

2.610 

85.080 

12.000 

2.050 

.0060 

Beehive  oven 

.0 

1.87 

1.120 

87.110 

11.770 

1.800 

.0110 

Beehive  oven 

.0 

.84 

.500 

1.130 

80.480 

16.470 

1.420 

.0140 

Beehive  oven 

.4 

1.74 

1.200 

87.400      11.550 

1.890 

.0130 

Beehive  oven,  B  seam 

.9 

1.89 

1.200 

89.250        9.550 

1.460 

.0160 

Beehive  oven,  B  seam 

.4 

.47 

1.500 

89.800 

8.210 

.460 

.0300 

Beehive  oven,  B  seam 

.6 

.92 

.220- 

.736 

86.100 

11.970 

1.700 

f  Latrobe  coal,  coked  in  Germany 
\      retort  oven 

.0 

.88 

.094 

.174 

85.753 

11.544 

2.435 

.0640 

Beehive 

.6 

.75 

.153 

.810 

92.760 

6.940 

.740 

.0066 

Beehive 

.5 

.37 

.430 

1.040 

91.560 

6.360 

.610 

.0130 

Beehive,  Hull,  Wyman,  &  Cairns 

.6 

.77 

1.140 

.410 

94.660 

3.780 

.590 

.0070 

Beehive,  Cumberland  colliery 

.6 

.86 

.017 

2.900 

91.048 

7.548 

.626 

.0070 

Beehive,  48-hour  coke 

.0 

.82 

4.000 

2.900 

84.330 

8.770 

1.670 

.0100 

Beehive,  48-hour,  unwashed  coal 

.1 

.82 

.230 

.800 

89.770 

9.800 

.976 

.0390 

Beehive,  72-hour,  washed  coal 

.5 

.67 

.290 

1.320       92.050 

5.600 

.740 

.0090 

Beehive,  48-hour  coke 

.7 

.61 

.630 

1.930  1    93.810 

3.630 

1.010 

.0050 

Beehive,  72-hour  coke 

.5 

.83 

.345 

.341 

92.694 

5.822 

.738 

.0063 

Beehive 

'8 

.89 

.130 

.376 

87.930 

10.270 

.790 

Beehive 

.1 

.92 

.614 

1.020 

84.667 

12.234 

1.465 

.0241 

Beehive 

1 

.77 

.430 

1  .  390 

83.070 

14.240 

.820 

.0190 

Beehive,  washed  coal 

.5  !     .89 

1  .  350 

83.800 

14.850 

1.080 

.0050 

Beehive,  washed  coal 

.5        .84 

.060 

95.000 

4.260 

.685 

.0180 

.6        .91 

.230 

.920 

86.040 

12.810 

.560 

.0050 

Semet-Solvay  oven 

.3 

.90 

.360 

1.290 

89.360 

8.990 

.760 

.0110 

Beehive  oven 

.8 

.95 

2.270 

78.881 

9.393 

.676 

Wyoming 

.9 

.95 

.120 

.740 

89.030 

10.110 

.690 

.0120 

Otto-Hoffman  oven,  Connellsville  coal 

9        .69 

.460 

1.770  !    84.330 

13.440 

1.770 

.0260 

Choctaw  Coke  Co.,  beehive 

.6        .81 

1.000 

1.200       87.310        9.400 

1.090 

.0160 

McCreary  Coke  Co. 

.0        .84 

.130 

1.220  !    87.750       10.900 

.990 

.  0280 

North  Connellsville,  beehive 

.0        .80 

.200      1.350  i    89.220 

9.230 

1.430 

.0180 

Beehive  oven,  Pittsburg  coal 

.0   i     .94 

.140      2.140  1    90.370 

7.420 

.960 

.0300 

Talladega  Furnace  Co. 

.9  !     .81 

.910      1.620       87.150 

10.320 

.970 

.0140 

Cumberland  plateau,  beehive 

5        .75 

.072 

.798  :    94.657 

3.775 

.698 

.0030 

8        .78 

2.480 

.270  I    87.409 

9.073 

.768 

.0080 

Upper  Freeport  coal,  beehive 

9        .74 

.860 

.914  i    88.679 

9.815 

.  506 

.0070 

No.  3 

0 

.80 

.142 

1.033       92.744 

5.630 

.451 

.0030 

No.  4 

.7 

.75 

.126 

.979  j    92.423 

5.925 

.547 

.0030 

No.  5 

0      1.79 

.003       91.690 

8.410 

.972 

.0021 

Gas  coal  seams 

0      1.75 

.250       92.480 

7.270 

.850 

.0010 

Screenings  from  whole  coal  bed  —  gas 

n,  F.  S.  Hyde,  J.  D.  Pennock,  O.  O.  Laudig,  and  E.  H.  Williams. 


TREATISE  ON  COKE  335 

proportion  as  it  approached,  in  size,  the  worthless  condition  of 
breeze.  The  destructive  action  of  the  use  of  small  coke  in  the 
Sydney  blast  furnaces  is  a  cautionary  example  in  this  respect. 


COMPARISON  OF  BEEHIVE  AND  BY-PRODUCT  COKING 

The  following  physical  and  chemical  determinations  made  in 
a  series  of  experimental  tests  in  coking  Connellsville  coal  in  the 
Otto-Hoffman  oven,  and  in  testing  Connellsville  and  Tuscarawas 
coals  in  the  Hiissner  ovens  in  Germany,  as  shown  in  Table  VII, 
will  exhibit  the  properties  of  the  cokes  made  in  these  ovens.  The 
Connellsville  standard  beehive  coke  is  given  for  comparison. 

The  analyses  of  the  coals  used  in  these  coking  tests  are  as 
follows  (Hugo  Carlsson,  chemist) : 

CONNELLSVILLE,  PA.      TUSCARAWAS,  OHIO 

PER  CENT.  PER  CENT. 

Moisture,  212°  F 840  2.530 

Volatile  combustible  matter 31 . 600  44 . 1 10 

Fixed  carbon 59 . 860  46 . 280 

Ash 7.700  7.080 

Sulphur 820  3. 490 

Phosphorus .  008  . 004 

Theoretic  coke 68 . 060  55 . 450 

The  analyses  of  the  cokes  made  from  the  above  coals  follow : 

CONNELLSVILLE,  PA.     TUSCARAWAS,  OHIO 

PER  CENT.  PER  CENT. 

Moisture,  212°  F 030  . 130 

Volatile  combustible  matter. ...          .  510  2 . 750 

Fixed  carbon 86.380  84.210 

Ash 13.080  12.910 

Sulphur .630  3.710 

Phosphorus 015  .015 

The  product  of  marketable  coke  from  the  Connellsville  coal  is 
given  at  70.10  per  cent.;  the  coke  from  the  Tuscarawas  coal 
is  stated  at  61.47  per  cent.  The  percentage  of  breeze  and  ashes  is 
not  given  separately,  but  these  have  no  value  in  blast-furnace 
work. 

As  the  Connellsville  coal,  in  retort  ovens,  affords  70.10  per  cent, 
of  useful  coke,  it  will  require  1.426  tons  of  coal  to  make  1  ton  of 
coke.  The  theoretic  product  of  coke  from  this  coal,  68.06  per 
cent.,  would  require  1.469  tons  of  coal  to  make  1  ton  of  coke, 
showing  a  gain  from  deposited  carbon  in  coking  of  2.9  per  cent. 

The  Tuscarawas  coal  gives  55.45  per  cent,  of  theoretic  coke, 
requiring  1.80  tons  of  coal  to  make  1  ton  of  coke.  As  the  oven 
yield  is  61.47  per  cent.,  the  deposited  carbon  is  9.79  per  cent., 
exhibiting  this  large  accretion  of  carbon  from  the  tar  of  this  rich 
bituminous  coal.  It  will  be  readily  seen  that,  in  the  process  of 
coking  the  Connellsville  coal  in  the  Hiissner  oven,  45  per  cent,  of 


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TREATISE  ON  COKE  337 

the  sulphur  has  been  volatilized.  In  coking  the  Tuscarawas  coal, 
46  per  cent,  of  the  sulphur  has  been  eliminated.  The  Tuscarawas 
coke  is  too  high  in  sulphur  for  use  in  the  manufacture  of  pig  iron. 
The  largest  volume  of  the  sulphur  in  the  Tuscarawas  coal  is  found 
as  bisulphide  of  iron,  FeS2.  In  the  process  of  coking,  one  equiva- 
lent of  sulphur  is  volatilized,  leaving  the  monosulphide,  FeS,  in 
the  coke.  Disintegrating  and  washing  this  quality  of  Ohio  coals 
would  reduce  the  sulphur. 

In  furnace  operations,  about  4  per  cent,  of  the  sulphur  goes 
over  to  the  pig  iron.  As  the  Connellsville  coke  contains  .63  per 
cent,  of  sulphur,  it  would  contribute  to  the  pig  iron  .0252  per  cent, 
of  this  element,  which  would  be  slightly  increased  from  the  sulphur 
in  the  ore  and  flux,  but  these  are  usually  small.  The  sulphur 
limit  in  the  best  Bessemer  pig  is  .04  to  .05  per  cent. 

In  examining  the  physical  structure  of  these  cokes,  the  effects 
of  the  Hiissner  oven  in  exerting  a  certain  pressure  to  the  charge 
in  coking  are  quite  evident  in  both  these  cokes. 

There  are  three  sections  of  different  densities  in  the  structure 
of  these  cokes,  as  shown  in  Fig.  1.  Beginning  on  the  sides  of  the 


(a)     Connellsville  (b)     Tuscarawas 

FIG.  1.     COKE  FROM  HUSSNER  OVEN 

oven,  section  a  contains  1  to  2  inches  of  the  most  dense  portion. 
Section  6,  6  to  6J  inches  long,  contains  fairly  well  developed 
cellular  structure.  Section  c,  next  to  the  middle  division  of  the 
coal  in  coking,  is  greatly  inflated  in  its  cells,  extending  about 
3  inches  from  its  central  end. 

In  making  the  determinations  •  shown  in  Table  VII,  Connells- 
ville coke  made  in  beehive  ovens  was  tested  by  three  samples  each 
of  48-  and  72-hour  coke.  The  table,  therefore,  affords  a  general 
average  of  the  physical  properties  of  this  standard  coke. 

In  the  Connellsville  and  Tuscarawas  cokes,  made  in  Germany, 
in  the  Hiissner  retort  oven,  four  samples  of  each  quality  of  coke 
were  used.  The  table  gives  these  determinations  in  full,  with  the 
general  averages  of  each  kind  for  comparison. 

The  tests  of  the  coke  from  Mr.  Frick's  Connellsville  coal,  made 
in  Germany,  in  the  Otto-Hoffman  oven,  consisted  of  two  average 
samples  from  the  top  and  bottom  of  the  oven. 

The  determinations  of  the  physical  properties  of  the  Hussner- 
Connellsville  coke  show  considerable  variation  in  density,  the 


338 


TREATISE  ON  COKE 


general  averages  exhibiting  an  increased  density  of  structure 
from  the  beehive-Connellsville  of  7.7  per  cent.  The  coke  is  lumpy. 
It  shatters  easily  into  finger  pieces,  on  planes  nearly  at  right 
angles  to  the  side  walls  of  the  oven.  It  does  not  inherit  the  sil- 
very coating  that  gives  the  beehive-Connellsville  coke  such  a  desir- 
able appearance. 

The  Hiissner-Connellsville  coke  is  somewhat  harder-bodied 
than  the  beehive-Connellsville  coke.  It  is  probable  that  the 
increased  hardness  of  body  of  the  former  will  compensate  for  the 
carbon  glaze  of  the  latter.  Both  hardness  of  body  and  carbon 
coating  protect  coke  in  its  passage  down  a  blast  furnace  from  the 
dissolving  agency  of  hot  carbon  dioxide. 

The  Hiissner-Tuscarawas  coke  is  lumpy  and  dark-colored, 
shattering  quite  easily  under  slight  shocks  into  slender  pieces,  on 
similar  planes  as  the  Hiissner-Connellsville  coke. 

The  Otto-HofTman-Connellsville  coke  is  the  hardest-bodied  fuel, 
exhibiting  good  work  in  the  oven.  But  its  largely  increased 
density  reduces  its  value  as  a  vigorous  blast-furnace  fuel.  It  is, 
on  a  general  average,  45  per  cent,  denser  than  the  standard  bee- 
hive-Connellsville coke,  and  40.4  per  cent,  denser  than  the  Hussner- 
Connellsville  product.  It  approximates  in  its  most  dense  sections 
to  anthracite.  It  may  be  submitted,  however,  that  the  samples 
furnished  by  Dr.  F.  Schniewind  were  very  select  as  to  complete- 
ness in  coking  and  density  of  structure. 

It  has  been  determined,  by  actual  furnace  work,  that,  for  the 
attainment  of  the  maximum  efficiency  of  coke  fuel  in  metallurgical 
operations,  two  prime  elements  are  absolutely  necessary:  hardness 
of  body  and  fully  developed  cell  structure. 

The  following  table  will  show  the  work  of  fuels,  accurately 
determined,  for  calorific  energy  and  economy  in  American  blast 
furnaces : 

TABLE  VIII 


- 

.c 

^ 

| 

* 

S  c 

CJ  fl( 

FH 

Size  of 

o 

UQ 

^  s 

Kind  of  Fuel 

Furnace 

&    w 

Location 

7)5 

3 

Year 

Remarks 

Feet 

"5  8 

See 

rtt-t 

^S 

6 

1 

I 

Charcoal  

12  by  60 

3,379 

Wisconsin.  .  .  . 

55 

1,815 

1891 

Bav  Furnace 

Anthracite  
Anthracite  and  coke  . 
Coke  

17  by  65 
15i  by  55i 
22  by  90 

2,698 
2,565 
12,000 

New  Jersey.  .  . 
Pennsylvania 
Pennsylvania 

55 
58 
59 

2,244 
2,200 
1,800 

1890 
1885 
1892 

Secaucus  Furnace 

Edgar  Thompson 
Connellsville  coke 

From  the  foregoing  results  in  blast-furnace   practice,   it  will 
appear  that  in  the  physical  condition  of  the  fuels  two  conditions 


TREATISE  ON  COKE 


339 


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342  TREATISE  ON  COKE 

have  been  established,  with  their  relative  consumption  of  fuel  and 
pig  iron  produced.  The  first  is  the  work  of  the  Connellsville 
standard  coke  in  the  Edgar  Thompson  blast  furnaces,  where  the 
smelting  of  1  ton  of  Bessemer  pig  iron  has  been  accomplished  with 
1,800  pounds  of  coke.  In  the  other,  2,200  pounds  of  anthracite 
was-  required  to  perform  similar  work. 

The  monthly  outputs  of  the  coke  and  anthracite  fuels  indicate 
their  relative  calorific  energies.  As  this  great  difference  in  fuel 
energy  has  not  its  source  in  their  chemical  composition,  it  follows 
that  it  must  be  found  in  their  physical  structure. 

In  this  structure  there  are  two  terms  of  relative  density:  in 
the  anthracite  100  per  cent,  and  in  the  standard  Connellsville 
coke  44  per  cent.  It  is  self-evident  that  any  increase  in  the  density 
of  the  coke  toward  that  of  anthracite  is  just  so  much  of  an  approach 
to  this  slow-acting  fuel,  and  hence  its  value  in  furnace  work  is 
depreciated  in  direct  proportion ;  perhaps  more  so  in  the  coke  than 
in  the  anthracite,  as  the  latter  decrepitates  in  the  presence  of 
furnace  heat  and  thus  presents  enlarged  surfaces  to  the  combining 
gases  in  combustion,  while  the  coke  does  not  break  up  under  heat, 
and  is  therefore  directly  less  energetic. 

It  was  evidently  for  such  reasons  that  Sir  I.  Lowthian  Bell,  in 
comparing  the  work  performed  in  his  blast  furnaces  by  coke  made 
from  Bears  Creek  coal  in  beehive  and  Simon-Carves  retort  coke 
ovens,  remarks  as  follows: 

"(1)  Mixtures  from  collieries  usually  supplying  Clarence  works 
and  made  in  beehive  ovens,  100  per  cent. ;  (2)  Bears  Creek  coke 
made  in  beehive  ovens,  101.11  per  cent.;  (3)  Bears  Creek  coke 
made  in  Simon-Carves  retort  ovens,  111.11  per  cent. 

"In  comparing  the  two  kinds  of  Bears  Creek  coke,  1  and  2,  if 
No.  2  is  taken  as  a  100  per  cent.,  then  No.  3  will  stand  as  109.89 
per  cent.,  exhibiting  an  inferiority  of  nearly  10  per  cent,  in  effi- 
ciency in  smelting  1  ton  of  No.  3  iron.  The  average  consumption 
of  the  three  fuels  was  2,520  pounds,  2,548  pounds,  and  2,800  pounds, 
respectively. " 

Comparative    Yield    of    Coke    in    Different    Ovens. — On    the 

other  side,  with  careful  work  in  coking,  the  percentages  of 
large  coke  made  in  beehive  Hiissner,  and  Otto-Hoffman  ovens 
are  as  follows: 

PER  CENT. 

Beehive  oven 65 

Htissner  oven 70-72 

Otto-Hoffman 70-72 

The  yield  in  the  retort  ovens  is,  therefore,  nearly  9.02  per  cent, 
above  the  yield  afforded  by  the  beehive  oven.  This  increased 
yield  in  the  retort-oven  coke  will  compensate  in  part  for  its  increased 
density,  requiring  increased  quantity  to  perform  equal  work  with 
the  beehive  product.  In  the  investigation  of  the  comparative 


TREATISE  ON  COKE 


343 


merits  of  these  two  coke  fuels,  the  vital  inquiry  is,  Will  65  units 
of  beehive  coke  perform  as  much  work  in  the  blast  furnace  as 
72  units  of  the  denser  retort  fuel? 

It  may  be  noted  here  that  the  increased  product  of  coke  from 
the  retort  ovens  over  that  of  the  beehive  is  more  apparent  than 
real,  as  has  been  determined  in  blast-furnace  and  cupola  practice. 
The  Buffalo  blast-furnace  tests,  with  Semet-Solvay  and  Connells- 
ville-beehive  cokes,  illustrated  this  in  a  very  interesting  manner. 
Both  cokes  were  made  from  Connellsville  coal.  Their  chemical 
composition  was  as  follows: 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
Per  Cent. 

Semet-Solvay    . 

1  25 

1    61 

86    66 

10   48 

77 

Beehive 

19 

1    17 

89  02 

9   62 

90 

The  general  average  of  the  coke  to  smelt  1  pound  of  Bessemer 
metal  was:  Semet-Solvay,  1.028  pounds;  Connellsville-beehive, 
.956  pounds;  showing  7  per  cent,  of  excess  in  retort-oven  coke. 
The  beehive  coke  inherited  11.06  per  cent,  of  cells  more  than  the 
retort  product.  In  a  further  test  of  Connellsville  coal  in  Otto- 
Hoffman  retort  coke  ovens,  at  the  Glassport  plant,  the  yield  of 
coke  was  71  per  cent. 

The  composition  of  the  Otto-Hoffman  and  Frick  cokes  is  as 
follows : 


Moisture 
Per  Cent. 

Volatile 
Matter 
Per  Cent. 

Fixed 
Carbon 
Per  Cent. 

Ash 
Per  Cent. 

Sulphur 
-Per  Cent. 

Phos- 
phorus 
Per  Cent. 

Otto-Hoffman  

.12 

.74 

88.97 

10.10 

.70 

.012 

Frick-beehive  .... 

.52 

.098 

89.55 

8.95 

.84 

.022 

Melting  Power. — The  following  is  a  comparison  of  results 
obtained  from  these  tests  at  the  steel  works  of  the  Lorain  Steel 
Company,  September,  1898: 

With  the  use  of  by-product  coke,  9.71  pounds  of  iron  was 
melted  per  pound  of  coke;  with  the  Frick  coke,  10.64  pounds.  This 
shows  8.83  per  cent,  more  iron  melted  with  the  Frick  beehive 
coke  than  the  Otto-Hoffman  product.  The  speed  in  melting  was 
decidedly  on  the  side  of  the  former  coke,  but  it  must  be  submitted 
that  there  are  economies  in  the  retort-coke-oven  work.  Taking 
the  relative  percentages  of  useful  coke  produced  by  these  two 
systems  at  71  per  cent,  and  65  per  cent.,  respectively,  it  is  evident 
that  the  retort  coke  will  only  require  1.41  tons  of  coal  to  make 


344  TREATISE  ON  COKE 

1  ton  of  coke,  and  the  beehive  1.54  tons,  showing  8.45  per  cent, 
of  economy  in  the  coal  used  in  the  retort  oven.  This  nearly 
balances  the  loss  in  the  retort  coke  in  the  blast  furnace.  Some 
economy  in  the  labor  of  making  the  retort  coke,  as  well  .as  in 
the  saving  of  the  by-products  of  gas,  tar,  and  ammoniacal  liquor, 
less  the  increased  cost  of  the  retort  oven  over  the  beehive,  will 
reduce  the  net  margin  of  saving  to  about  30  cents  per  ton  of  coke 
produced. 

It  has  been  found  quite  difficult  to  procure  an  accurate  state- 
ment of  the  work  and  cost  of  making  coke  in  the  retort  coke  ovens, 
especially  the  cost  of  repairs.  The  tabulated  statements,  Tables 
IX,  X,  XI,  XII,  and  XIII,  will  throw  some  light  on  these  matters: 

TABLE  XI 

COST  AND  PRODUCTION  OF  OTTO-HOFFMAN  COKE  OVENS  AT  JOHNS- 
TOWN, PENNSYLVANIA,  FISCAL  YEAR  1898-1899 

COST 
AMOUNT  TOTALS      PER  TON 

Superintendents,      assistants,     clerks, 

chemist,  pumping  station $  6,914.40 

Labor  on  coal 7,826 . 78 

Labor,  washing  and  mixing  coal,  and 

team  service 2,808. 91 

Labor  at  ovens 39,845. 14  $57,395. 23  $  . 425 


Repairs  to  ovens 3,464. 55 

Repairs   to   tracks,    pumping   station, 

and  general  repairs 2,100.67 

Coal-mixing  machinery 4,550 . 70  10, 1 1 5 .  92  . 075 


Oil,  waste,  packing,  tools,  etc 2,998.84 

Transportation 6,005. 25 

Loam  and  clay 343 . 80 

Office  expenses  and  incidentals 4,653.72 

Coal  for  steam  and  heating  ovens 7,425.04  21,426.65  . 158 


General  expenses 2,319.91  .017 

Taxes 1,222.00  .009 


Cost  of  coking 92,481 . 71  . 684 

213,761.64  net  tons  coal  at  .89.  .  190,372.68         1.409 


Gross  cost  of  coke 282,854. 39         2.094 

Credit  for  by-products 23.371 . 85  . 173 


Net  cost  135,083.40  net  tons  coke 259,482.  54         1 . 921 

Firing  new  ovens 4,955. 14  .039 

Mud-dam...  371.92 


29,089  ovens $264,809. 60       $1 .  960 


TREATISE  ON  COKE  345 

BY-PRODUCTS 

CREDIT  AMOUNT  TOTALS 
56,100,000  cubic  feet  of  gas  at  5  cents  per  thou- 
sand  $  2,805.00 

3,433.90  net  tons  of  tar  at  $5.06 17,366.83 

263.37  net  tons  sulphate  of  ammonia  at  $50.47  .    13,291.65 

275.37  net  tons  concentrated  liquor  at  $22.87    ..      6,297.89       $39,761.37 

DEBIT 

Labor  at  by-product  plant 10,958.  92 

Repairs  at  by-product  plant 1,518.49 

Lime  and  sulphuric  acid 3,547.97 

General  expenses 364 . 14         16,38-9 . 52 


Net  credit  for  by-products ;  .  .  .  $23,371 .85 

PRACTICE  .  PER  CENT. 

213,761.64  tons  coal  used  for  coke 

135,083.40  tons  scale  weight  coke  produced 63. 19 

3,433.90  tons  tar  produced , 1.61 

263.37  tons  sulphate  produced .12 

275.37  tons  concentrated  ammonia  liquor  produced .13 

CUBIC  FEET 
Gas 262 

TABLE  XII 

COST  AND  PRODUCTION  OF  OTTO-HOFFMAN  COKE  WORKS,  FISCAL 

YEAR   1895-1896 

COST 

AMOUNT  TOTALS         PER  TON 

Superintendents,      assistants,      clerks, 

chemists,  pumping  station $  6,489. 14 

Labor  on  coal 3,302 . 09 

Labor  at  ovens 24,612.96          $34,404.19       $   .653 


Repairs  to  ovens 14,298.20 

Repairs   to   tracks,    pumping    station, 

and  general  repairs 2,370.04             16,668.24            .317 

Oil,  waste,  packing,  tools,  etc 3,326 . 78 

Transportation. 2,722. 75 

Loam  and  clay 311 . 17 

Office  expenses  and  incidentals 1,311 .77 

Coal  for  steam  and  heating  ovens. ....  7,843.60             15,516.07            .295 

General  expenses 1,937. 37 

Taxes 80.00              2,017.37            .038 


Cost  of  coking 68,605 .87         1 . 303 

66,965.62  net  tons  coal  at  $.  98 65,681. 63         1 .  274 


Gross  cost  of  coke 134,287 . 50         2  550 

Credit  for  by-products 5,281 . 64  . 100 

Net  cost  52,666.43  net  tons  coke.. .  $129,005.86       $2.450 


346  TREATISE  ON  COKE 

BY-PRODUCTS 
CREDIT  AMOUNT  TOTALS 

Cubic  feet  gas  at 

1,635.75  net  tons  tar,  at  $5.95 $  9,713.71 

302.62  net  tons  sulphate  of  ammonia,  at  $39.99   12,100.69       $21,814.40 


DEBIT 

Labor  at  by-product  plant. .  . 11,387. 26 

Repairs  at  by-product  plant 902 . 20 

Lime  and  sulphuric  acid 4,243  30         16,532 . 76 

Net  credits  for  by-products $5,281 . 64 

PRACTICE  PER  CENT. 

66,965.62  tons  coal  used  for  coke 

52,666.43  tons  scale  weight  coke  produced. 

52,666.43  tons  coke  credited 78. 65 

1,636.75  tons  tar  produced , 78.  65 

302.62  tons  sulphate  produced 2. 44 

CUBIC  FEET 
Gas. 45 

TABLE  XIII 

COST  OF  MAKING  COKE  IN  BEEHIVE  OVENS 

CENTS 

Drawing  coke 1800 

Leveling 0200 

Yard  boss,  $75  per  month 0050 

1   locomotive  engineer,  $12.25  \  nnon 

1  charger,  $1.68  per  day  /  ' ' 

1  track  cleaner,  1  car  trimmer,  $1.35  per  day 0040 

1  car  shifter,  $1.75  per  day 0030 

1  track  man,  $1 .50  per  day 0020 

3  cart  horses 0040 

Water 0100 

Half  superintendent's  salary,  $175  per  month 0050 

Repairs 0300 

Interest  on  investments     .0030 

Taxes,  insurance,  etc .  0250 

Coke  working  extra .  0250 

3520 

1 .5  tons  of  coal  at  89  cents  per  ton $1 . 3350 

Repairs  per  ton  of  coke 0135 

Total $1 . 7005 

Johnstown,  Pa.,  April  1,  1899. 

Table  IX  exhibits  the  time  required  to  make  1  ton  of  coke  in 
Otto-Hoffman  coke  ovens  at  Glassport  and  Johnstown,  Pennsyl- 
vania, with  the  time  used  at  Holland.  No.  3,  Germany. 

Table  X  affords  in  full  details  the  several  departments  of  labor 
in  making  coke  and  saving  by-products,  with  the  aggregate  cost  of 
each  department,  as  the  relative  cost  per  ton  for  labor,  in  Glassport 
and  Johnstown. 


TREATISE  ON  COKE  347 

Table  XI  affords  the  cost  of  the  several  elements  of  labor 
and  materials  required  in  making  1  ton  of  coke  and  saving  by- 
products. It  also  affords  the  ultimate  aggregate  cost  of  coke, 
charging  the  cost  of  coal  at  89  cents  per  net  ton,  and  crediting 
the  manufacture  of  the  coke  with  the  value  of  the  saved  by-products, 
making  the  net  cost  of  1  ton  of  coke  $1.92,  including  ordinary 
repairs  of  ovens,  but  excluding  extraordinary  expenses. 

Table  XII  gives  cost  and  production  of  Otto-Hoffman  coke 
ovens  at  Johnstown  during  the  fiscal  year,  1895-1896.  Evidently 
these  costs  include  new  construction,  and  the  large  cost  per  net 
ton  of  coke  has  not  been  used  in  calculations.  The  moderate  cost 
of  $1.92  has  been  taken  for  comparison.  The  cost  of  maintenance 
of  these  Otto-Hoffman  coke  ovens  is  only  incidentally  afforded  in 
the  foregoing  tabulated  statements.  These  do  not  cover  a  suffi- 
cient length  of  time  to  give  reliable  data  in  this  important  element 
of  cost.  Taking  what  is  given  in  these  statements  of  the  minimum 
average  cost  of  repairs  per  net  ton  of  coke  produced,  with  the 
saving  of  the  by-products  and  avoiding  unusual  expenses,  it  is 
8  cents.  This  is  included  in  the  net  cost  of  $1.92  per  ton  of  coke 
made.  This  plant  of  coke  ovens  is  comparatively  new;  as  it  ages, 
the  cost  of  repairs  will  increase  largely. 

In  this  connection  it  may  be  interesting  to  compare  the  cost 
of  making  coke  in  the  Connellsville-beehive  coke  oven,  as  shown 
in  Table  XIII.  It  is  estimated  that  the  life  of  a  beehive  coke 
oven  is  16  years.  To  maintain  it  during  this  time  will  cost:  for 
bottoms,  $34.50;  tunnel  heads,  $32;  and  fronts,  $76;  making 
in  all  $142.50;  say,  $1.50  per  oven  during  the  16  years.  Taking 
the  average  annual  product  of  an  oven  at  700  tons,  the  cost  of 
repairs  will  be  $.0133  per  ton  of  coke.  Adding  this  to  the  cost  of 
making  coke,  will  give  the  total  net  cost  of  producing  coke  in  a 
beehive  coke  oven  at  $1.7005  per  net  ton,  showing  an  economy 
on  the  side  of  the  beehive  of  $.2195,  as  compared  with  the  work 
of  the  retort  ovens  at  Johnstown. 

It  is  not  assumed  that  the  cost  of  production  of  coke  at  the 
Johnstown  retort  coke  ovens  is  a  minimum  quantity,  but  it  indi- 
cates that  the  claims  of  large  profits  in  this  type  of  coke  oven  over 
the  ancient  beehive  oven  are  not  assured  in  the  foregoing  instances. 
When  the  great  difference  in  the  cost  of  these  ovens  is  considered, 
with  the  relative  interest  on  investment  in  plants,  the  economies 
will  still  be  increased  on  the  side  of  the  round  oven.  But  it  must 
be  considered  that  there  is  an  additional  credit  due  the  retort  oven. 
Taking  the  relative  product  of  coke  from  Connellsville  coal  at  65 
per  cent,  for  the  beehive  and  72  per  cent,  for  the  Otto-Hoffman, 
respectively,  it  is  evident  that  the  former  will  require  1.538  tons 
of  coal  to  make  1  ton  of  coke,  and  the  latter  1.39  tons  to  1  ton  of 
coke,  exhibiting  an  economy  in  the  use  of  coal  in  the  retort  oven 
of  296  pounds.  This,  at  89  cents  per  ton,  gives  $.132  of  credit  to 
the  retort  oven.  The  relative  costs  of  producing  coke,  per  net 


348  TREATISE  ON  COKE 

ton,  in  the  two  cases  under  consideration  are  as  follows:  beehive, 
$1.7005;  Otto-Hoffman,  $1.788,  thus  showing  substantially  equal 
cost  in  the  production  of  coke  by  these  types  of  coke  ovens. 

If  a  further  investigation  of  the  interest  in  investment  on  the 
plants  of  ovens  and  by-product  saving  is  considered,  with  the 
additional  fact  that  72  per  cent,  of  retort  coke  is  only  equal  to 
65  per  cent,  of  beehive  coke  in  blast-furnace  operations,  the  value 
of  the  retort  coke  ovens,  considered  in  this  comparison,  dissipates 
much  of  the  claims  for  economy.  But  their  essential  usefulness 
must  be  recognized  in  their  capacity  to  produce  coke  from  the 
dry  coals  that  could  not  be  made  into  good  coke  in  the  beehive 
ovens.  This  element  of  their  usefulness  will  increase  as  the 
coal  suitable  for  the  open-oven  manufacture  becomes  partially 
exhausted. 


EFFECTS  OF  THE  SEVERAL  TYPES  OF  COKE  OVENS  ON  THE  PHYSICAL 
PROPERTIES  OF  THEIR  COKE  PRODUCTS 

With  the  manufacturers  of  coke  for  metallurgical  uses,  the 
fact  is  well  established  that  coke  ovens  dominate,  in  a  large  degree, 
the  physical  properties  of  their  products.  It  is,  therefore,  now 
proposed  to  consider  the  relative  effects  of  the  typical  coke  ovens 
on  the  physical  -condition  of  the  coke  produced  in  each  kind.  It 
is  well  known  that  in  the  great  variety  of  coke  ovens  there  are 
only  three  root  types:  the  beehive,  or  round,  oven;  the  Knab,  or 
retort,  oven;  and  the  Appolt,  or  upright,  oven. 

In  the  beehive  and  other  horizontal  types  of  coke  ovens,  it  will 
be  readily  understood  that  the  governing  element  in  their  opera- 
tions is  similar;  a  broad  charge  of  coal,  24  to  26  inches  deep,  afford- 
ing the  greatest  liberty  to  the  charge  of  coal  in  fusing  to  develop 
the  fullest  cellular  structure  and  to  glaze  the  upper  portion  of  the 
coke  with  deposited  carbon,  giving  it  a  sheen  that,  in  addition  to 
its  appearance,  contributes  to  its  resistance  to  the  dissolving 
agency  of  hot  carbon-dioxide  gas  in  blast-furnace  and  cupola 
operations. 

The  moderate  heat  of  these  ovens,  in  the  initial  operations  of 
coking,  prevents  a  too  inflated  or  frothy  physical  structure  in  the 
coke.  The  physical  properties  of  the  coke  from  this  type  of  coke 
oven  are  most  excellent.  With  the  use  of  the  best  qualities  of 
coking  coals  in  the  manufacture  of  coke,  the  product  is  always 
the  best  possible  for  blast-furnace  use. 

This  family  of  coke  ovens  yields  63  to  66  per  cent,  of  marketable 
coke  with  2  to  3  per  cent,  of  small  coke  and  ash.  The  percentage 
of  coke  obtained  depends  on  the  skill  and  economies  applied  in 
the  coking  operations,  as  well  as  in  the  quality  of  the  coal  used. 

The  Knab  coke  oven,  with  its  numerous  offspring  of  these 
narrow  vertical  ovens,  has  chambers  18  to  24  inches  in  width 
and  25  to  35  feet  in  length.  The  Simon-Carves,  Semet-Solvay, 


TREATISE  ON  COKE  349 

Hiissner,  Seibel,  and  Otto-Hoffman  are  examples  of  this  type  of 
oven.  With  narrow  chambers  and  charges  of  coal  5  to  6  feet 
deep,  a  certain  amount  of  pressure  is  exerted  in  the  process  of 
coking,  producing  coke  of  increased  density  of  structure  as  com- 
pared with  the  product  of  the  round  or  the  horizontal  ovens. 
This  density  of  coke  is  readily  seen  near  the  side  walls  of  the  coking 
chamber,  and  especially  at  the  bottom  section  of  the  oven.  As 
the  coking  begins  at  the  sides  and  bottom  of  the  oven,  a  minimum 
quantity  of  carbon  is  deposited  from  the  gases  evolved  in  coking. 
From  the  great  heat  maintained  in  these  ovens  by  the  combustion 
of  gases  in  the  bottom  and  side  flues,  the  operation  of  coking 
begins  quickly  and  is  usually  accomplished  in  a  thorough  manner, 
avoiding  much  of  the  black  ends  that  occasionally  appear  on  coke 
from  the  horizontal  ovens. 

The  vertical  posture  of  the  chamber  of  the  Appolt  oven  confers 
on  its  coke  the  densest  physical  structure.  It  is  probable  that 
this  oven  could  be  used  in  the  manufacture  of  coke  from  coals 
very  rich  in  fusing  matter,  as  it  would  tend  to  repress  a  too  inflated 
structure  in  the  coke.  These  retort  coke  ovens  produce  from 
70  to  73  per  cent,  of  marketable  coke. 

Table  XIV  will  show  the  relative  influence  of  these  coke  ovens 
on  the  physical  properties  of  their  coke. 

In  this  table,  reference  letter  (a)  gives  the  average  phys- 
ical properties  of  the  standard  Connellsville  coke  made  in  the 
beehive  coke  oven.  This  general  average  embraces  samplings 
taken  in  the  coke  from  the  top,  middle,  and  bottom  of  the  charge. 
It  is  therefore  a  fair  average  of  the  best  quality  of  this  coke.  (6) 
gives  the  results  of  a  coking  test  made  in  a  Hiissner  retort  coke 
oven  in  Germany,  from  a  shipment  of  Connellsville  coal,  during 
the  early  movement  to  introduce  these  narrow  coke  ovens  into 
the  United  States  of  America.  Samplings  of  this  coke  were 
secured  from  the  side,  middle,  and  bottom  of  the  coke  made  in 
this  oven;  the  average  result  is  given  in  the  table,  (c)  exhibits 
the  physical  properties  of  coke  made  in  the  experimental  coking 
plant  of  the  Semet-Solvay  Company  at  the  Solvay  Chemical  Works, 
Syracuse,  New  York.  It  was  made  from  a  shipment  of  coal  from 
the  Connellsville  field  in  1895.  This  average  determination  of 
the  physical  properties  cff  this  coke  embraces  samplings  from  top, 
middle,  and  bottom  of  the  charges,  (d)  exhibifs  the  work  of  the 
Otto-Hoffman  retort  coke  oven,  from  a  shipment  of  Connellsville 
coal  sent  to  Germany  for  the  purpose  of  a  general  test.  The 
average  of  two  samplings  from  top  and  bottom  is  given  in  the 
table,  (e]  gives  the  physical  properties  of  coke  made  from  Morris 
Run  coal,  Tioga  County,  Pennsylvania,  in  a  beehive  coke  oven. 
(/)  exhibits  the  physical  properties  of  coke  made  in  a  Semet- 
Solvay  coke  oven  from  the  Morris  Run  coal.  The  design  was  to 
determine  the  influence  exerted  by  this  type  of  retort  coke  oven 
in  repressing  cellular  structure  in  the  coke,  as  compared  with  the 


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350 


TREATISE  ON  COKE  351 

product  of  the  beehive  coke  oven,  with  its  horizontal  posture  and 
freedom  of  action  in  coking,  (g) ,  (h) ,  (i) ,  (k) ,  and  (/)  afford  exam- 
ples of  the  physical  properties  of  cokes  made  from  different  qualities 
of  coals  in  beehive  coke  ovens,  (m)  gives  the  anthracite  or  natural 
coke.  It  has  no  cell  structure  and  is  the  most  dense  fuel  used  in 
blast-furnace  operations.  It  will  be  interesting  to  compare  the 
relative  percentage,  by  volume,  of  coke  to  cells  in  the  foregoing 
tests,  as  shown  in  Table  XV. 

TABLE  XV 

COKE  CELLS 

PER  CENT.  PER  CENT. 

(a)   Connellsville  beehive  standard  coke 43.  93  56.07 

(6)    Hiissner,  Connellsville  coal 48 . 24  51 . 76 

(c)  Semet-Solvay,  Connellsville  coal 49. 49  50 . 51 

(d)  Otto-Hoffman,  Connellsville  coal,  German  test     69.17  30.83 

(e)  Morris  Run  coal,  beehive  oven 41 .82  58. 18 

(/)    Semet-Solvay,  Morris  Run  coal 47.68  52.32 

(g),  W,  (*)»  (&).  and  (/)  beehive,  various  coals, 

general  average 44 .  78  55 . 22 

(m)    Anthracite,  general  average 100.00 

TABLE  XVI 

PER  CENT. 

Anthracite 100 . 00 

Connellsville  standard  beehive  coke 43 .  93 

Hiissner,  Connellsville  coal,  Germany 48. 24 

Otto-Hoffman,  Connellsville  coal,  Germany 69. 17 

Otto-Hoffman,  Connellsville  coal,  Glassport,   Pennsyl- 
vania    53 . 73 

Semet-Solvay,  Connellsville  coal,  Syracuse,  New  York.  50. 12 

Morris  Run  coke,  beehive  oven 41 . 82 

Morris  Run  coke,  Semet-Solvay  ovens   47 . 68 

Average  of  all  retort-oven  coke,  Connellsville  coal  ....  55.72 

Average  of  all  beehive  ovens  on  various  coals 42 . 88 

The  above  statements  will  exhibit  in  a  brief  manner  the  effects 
of  the  different  types  of  coke  ovens  in  repressing  the  physical 
structure  of  the  coke,  as  compared  with  anthracite  at  100  per  cent. 
Direct  comparisons  can  thus  be  made  of  the  coke  products  of  the 
beehive  and  retort  types  of  coke  ovens. 

Taking  the  volume  of  the  body  of  the  beehive-Connellsville 
coke  at  43.93  per  cent.,  and  the  Hiissner  coke  from  Connellsville 
coal  at  48.24  per  cent.,  the  latter  retort  oven  has  compressed  its 
coke  8.94  per  cent.  The  Semet-Solvay  oven,  using  Connellsville 
coal,  compresses  its  product  11.23  per  cent.  The  Otto-Hoffman, 
using  Connellsville  coal,  compresses  its  product  24.49  per  cent. 
The  general  average  of  the  retort  coke  ovens  represses  their  product 
21.03  per  cent. 

But  we  have  a  very  interesting  test  of  the  effects  of  the 
beehive  and  Semet-Solvay  ovens,  using  Morris  Run  coal,  on 
their  coke  product.  The  beehive  oven  gives  the  coke  a  cellular 


352  TREATISE  ON  COKE 

structure  of  58.18  per  cent.,  while  the  Semet-Solvay  retort  oven 
gives  only  52.32  per  cent,  of  cells  in  its  coke,  a  difference  of  11.02 
per  cent,  in  favor  of  the  beehive  structure;  or,  in  other  words, 
the  retort  oven  densities  its  coke  11.02  per  cent,  over  that  of 
the  round  or  beehive  oven. 

It  follows,  therefore,  that,  as  the  calorific  energy  of  any  fuel  is 
in  proportion  to  the  extent  of  its  surface  exposed  to  the  oxidation 
agencies  in  a  blast  furnace,  then  the  greater  this  surface,  within 
certain  limits,  the  more  energetic  the  combustion  As  anthracite, 
or  natural  coke,  is  the  most  dense  of  fuels  and  the  least  energetic 
in  its  combustion,  it  follows  that,  in  the  preparation  of  artificial 
fuel  in  coke  ovens,  every  approach  in  the  density  of  the  coke  to 
that  of  anthracite  reduces  its  calorific  energy  and  therefore  its 
value  for  blast-furnace  operations. 

Of  course  in  this  conclusion,  the  economy  of  the  work  in  pro- 
ducing coke  in  the  retort  ovens,  with  the  additional  revenue 
derived  from  the  by-products,  must  be  considered  as  an  offset  of 
credit  against  the  density  of  the  coke.  But  if  the  prime  effort  is 
to  produce  the  most  energetic  fuel  for  blast-furnace  work,  then 
the  repression  of  the  cells  and  the  densification  of  the  coke  in  the 
narrow  ovens  cannot  be  defended. 


CHAPTER  VIII 


THE  LABORATORY  METHODS  OF  DETERMINING  THE  RELA- 
TIVE CALORIFIC  VALUES  OF  METALLURGICAL  FUELS 

There  can  be  little  difference  of  opinion  in  deciding  that  the 
test  in  blast-furnace  use  of  the  three  principal  fuels  is  the  most 
reliable  method  of  determining  their  relative  calorific  values,  pro- 
vided the  conditions  of  the  work  are  equalized  justly. 

This  assumes  that  such  tests  shall  have  been  made  in  blast 
furnaces  whose  dimensions  have  been  proportioned  to  assure  the 
best  possible  results  in  the  fuel  used';  not  only  this,  but  that  the 
pressure  and  heat  of  blast  have  been  in  harmony  with  the  require- 
ments of  the  fuels,  in  order  to  accomplish  their  complete  combus- 
tion and  economical  application. 

It  is  further  assumed  that  in  these  practical  determinations 
of  the  calorific  values  of  these  fuels  in  blast-furnace  work,  three 
chief  considerations  shall  have  been  accurately  noted:  (1)  The 
weight  of  fuel  to  smelt  1  ton  of  pig  iron;  (2)  the  time  required  in 
smelting;  and  (3)  the  purity  of  the  fuel.  The  first  shows  the 
economy  in  fuel;  the  second,  economy  in  the  cost  of  superintend- 
ence; and  the  third,  exemptness  from  dangerous  impurities  in  the 
pig  metal  produced. 

The  table  on  page  354  exhibits,  approximately,  the  work  of 
the  three  chief  fuels  in  blast-furnace  operations. 

Equating  the  results  shown  in  the  table  to  approximately  equal 
practical  conditions,  the  relative  calorific  efficiency  of  these  three 
fuels  will  stand  as  follows:  Coke,  100  per  cent.;  charcoal,  90  per 
cent.;  anthracite,  78  per  cent. 

It  is  submitted  that  the  statements  in  the  table  of  blast- 
furnace work  are  practical  general  averages.  They  are  greatly 
exceeded  by  recent  work,  as  will  be  seen  in  the  following 
statement : 

"Furnace  No.  1  of  the  Carnegie  Steel  Company,  at  Duquesne, 
Pennsylvania,  has  just  made  a  record  for  long  blast  on  one  lining 
and  for  output  that  will  probably  stand  for  some  time.  This  fur- 
nace was  blown  in  on  June  8,  1896,  and  was  in  continuous  blast 
until  October  21,  1903,  a  period  of  7  years,  4  months,  and  13  days. 
During  its  blast,  the  furnace  turned  out  1,287,400  gross  tons  of 
Bessemer  pig  iron.  The  best  day's  record  was  on  October  26, 

353 


354 


TREATISE  ON  COKE 


1898,  when  the  furnace  made  748  tons  and  350  pounds.  The  best 
week's  work  was  for  the  week  ending  October  29,  1898,  when  the 
furnace  made  4,990  tons  and  209  pounds.  The  best  month's 
work  was  October,  1898,  when  the  product  was  18,672  gross  tons 
of  Bessemer  iron.  The  average  coke  consumption  per  ton  of  pig 
iron  was  2,020  pounds.  This  furnace  is  100  feet  by  22  feet  in 
size.  It  will  be  repaired  and  relined." 

COMPARATIVE  WORK    OF  FUELS  IN  BLAST  FURNACES 


&    ' 

c 
"    +^  8 

I°C 

o-             e 

+j  •'-'  H 

o  ctf  S"""1 

*o  o  2 

Kind  of  Fuel 

Furnace 

aj  % 

Location 

c  fe^'3 

m****0 

General  Remarks 

O     O 

£<£| 

I~2Z 

PL, 

Charcoal  

10'  5"  X  45' 

1,488 

Michigan 

59.00 

1,844 

f  Spring  Lake  Furnace, 
(      Lake  ore 

Charcoal  
Charcoal  

10'  X  48' 
12'  X  60' 

2,615 
3,379 

Michigan 
Wisconsin 

60.00 
55.00 

2,060 
1,815 

Bay  Furnace,  Lake  ore 
f  Hincle  Furnace,  Ash- 
S       i      -i 

(      land 

Averages  

2,494 

58.00 

1,907 

Anthracite  

17'X65' 

2,698 

New  Jersey 

55.00 

2,244 

f  Secaucus,  Hudson 
(      Company 

(No.    9    Furnace,    75 

Anthracite  

16'  6"  X  65' 

2,376 

New  Jersey 

55.21 

2,347 

<  per  cent,  coal,  25  per 

(     cent  coke 

Averages  
Coke  

22'X90' 

2,537 
10,536 

New  Jersey 
Pennsylvania 

55.10 
59.00 

2,295 
1,737 

f  Edgar  Thompson, 
(      Connellsville  coke 

Coke           

22'  X  90' 

12,000 

Pennsylvania 

59.00 

1,800 

f  Edgar  Thompson, 

(     Connellsville  coke 

Coke  

22'  X  100' 

17,700 

Pennsylvania 

59.00 

1,850 

f  Duquesne  Furnace, 
\      Carnegie  Steel  Co. 

Averages  

13,412 

Pennsylvania 

59.00 

1,796 

It  is  further  submitted  that  the  above  practical  results,  in 
actual  furnace  work,  afford  sure  standards  for  laboratory  deter- 
minations of  the  value  of  fuels  for  metallurgical  purposes.  It  has 
been  shown  that  the  two  chief  essential  physical  requirements  in 
fuel  for  blast-furnace  use  are  hardness  of  body  and  well-developed 
cell  structure. 

The  first  essential  physical  requirement  of  hardness  of  body  is 
important  in  protecting  the  fuel  in  its  downward  passage  in  a 
blast  furnace  from  loss  in  dissolution  by  carbon  dioxide.  Sir 
I.  Lowthian  Bell  long  ago  pointed  out,  first,  "that  the  carbon,  as  it 
exists  in  different  qualities  of  coke,  is  not  influenced  in  the  same 
degree  by  this  solvent  power  of  CO2\  second,  that  the  soft  descrip- 
tion, known  as  black  ends,  is  more  easily  attacked  than  the  hard, 
silvery -looking  kind." 

In  two  tests,  with  hard-  and  soft-bodied  coke,  Mr.  Bell  proves 
that  the  hard  coke,  pulverized  to  the  size  of  mustard  seed,  exposed 
at  a  temperature  of  melting  zinc  for  f  of  an  hour  to  a  current 
of  CO2  gave  a  mere  trace  of  CO.  The  soft  coke,  similarly  treated, 
in  \\  hours  gave  92  cubic  centimeters  of  CO.  This  indicates  the 


TREATISE  ON  COKE  355 

loss  that  the  soft  variety  of  coke  suffers  by  dissolution  in  the 
blast  furnace  is  nearly  8  per  cent. 

In  the  second  requirement,  the  valuable  results  from  full 
development  of  cells  in  coke  are  readily  understood,  as  these  cell 
spaces  afford  free  entry  to  the  ascending  hot  gases,  which  thus 
permeate  the  coke  thoroughly  and  impart  to  it  a  high  temperature, 
which  aids  materially  in  its  rapid  combustion.  In  addition  to 
this,  the  large  area  of  the  cell  spaces  affords  ample  surface  for  the 
hot  oxygen  of  the  blast  to  act  on,  securing  rapid  combustion  with 
high  temperature  and  calorific  energy,  resulting  in  the  rapid  work- 
ing of  the  furnace. 

Now  anthracite  is  not  lacking  in  hardness  of  body;  in  this 
physical  property  it  is  equal  to  the  average  cokes.  We  have  seen, 
however,  that  it  requires  2,347  pounds  of  anthracite  to  do  the 
work  of  1,796  pounds  of  coke  in  a  blast  furnace.  It  is  evident, 
therefore,  that  the  property  of  hardness  of  body  alone  will  not 
afford  the  best  results  in  smelting  pig  iron.  The  great  density  in 
this  fuel  confers  on  it  the  slowest  combustion  in  a  blast  furnace. 
Only  for  the  decrepitation,  which  takes  place  near  the  tuyeres, 
its  rate  of  combustion  would  be  further  retarded. 

On  the  other  hand,  coke  possesses  an  average  hardness  equal 
to  the  anthracite;  but  any  slight  difference  of  hardness  of  body 
cannot  be  urged  to  account,  in  any  important  degree,  for  the 
great  difference  in  the  calorific  energy  of  coke  over  anthracite  in 
blast-furnace  operations. 

As  the  difference  in  the  calorific  efficiency  of  these  fuels  has 
not  its  exclusive  genesis  in  the  physical  property  of  hardness  of 
body  alone,  it  is  evident  that  it  must  be  looked  for  elsewhere. 
This  has  been  discovered  to  be  in  the  cellular  structure  of  the 
coke,  other  conditions  being  equal. 

In  the  best  varieties  of  coke  the  aggregate  volume  of  the  cell 
spaces  to  the  body  of  the  coke  is  as  44  to  56  nearly.  In  some 
cokes,  this  cell  structure  is  too  inflated,  conferring  on  it  brittleness 
in  furnace  work,  with  lack  of  energy  at  the  tuyeres. 

From  these  conditions,  in  the  anthracite  and  coke  fuels,  it  is 
evident  that  in  the  best  varieties  of  each  we  have,  from  actual 
work  in  the  furnace,  two  different  results:  in  the  anthracite,  a 
dense,  languid  fuel,  and  in  the  coke  a  cellular,  vigorous  fuel.  The 
ratio  of  the  former  to  the  latter  in  calorific  energy  or  speed  is  as 
about  1  to  3,  assuming  that  they  have  about  the  same  or  equiva- 
lent chemical  composition. 

LABORATORY  TESTS 

From  these  tests  of  the  physical  properties  of  these  two  impor- 
tant metallurgical  fuels,  the  following  methods  of  determining  the 
values  of  all  qualities-  of  coke  for  blast  furnace  or  for  similar  uses 
have  been  established : 


356  TREATISE  ON  COKE 

Cell  Structure. — An  average  sample  of  the  coke  is  carefully  and 
accurately  cut  into  inch  cubes.  One  or  more  of  these  cubes, 
depending  on  the  accuracy  required  in  the  determinations,  is 
thoroughly  dried,  and,  when  cooled,  carefully  weighed.  This  gives 
the  weight  of  the  body  of  the  coke  in  its  dry  condition.  The 
cubes  are  then  immersed  in  a  vessel  of  distilled  water  and  put 
under  the  receiver  of  an  air  pump,  the  air  pumped  out  of  and  the 
water  forced  into  the  cells.  The  cube  or  cubes  are  again  weighed; 
the  difference  in  weight,  equated  to  the  specific  gravity  of  the  coke, 
gives  the  aggregate  cell  space  in  the  cube  of  coke. 

An  easier  method  is  suggested  by  the  late  Doctor  Sterry  Hunt, 
in  the  "Report  of  the  Geological  Survey  of  Canada,"  1863-6, 
pages  281-3. 

His  method  is  to  select  suitable  specimens  of  any  size  or  shape, 
usually  pieces  from  20  to  40  grams  in  weight ;  these  are  to  be  dried 
and  weighed;  then  fill  their  cells  with  water  and  weigh  in  water; 
the  pieces  are  then  taken  out  of  water,  the  excess  of  water  on 
their  surfaces  carefully  removed,  and  weighed  again  in  air.  These 
operations  furnish  all  necessary  data  for  calculating  the  following 
properties : 

1.  The  apparent  specific  gravity,  or  the  relationship  between 
the  whole  mass  of  material  and  an  equal  volume  of  water. 

2.  The  true  specific  gravity  or  the  specific  gravity  of  the  body 
of  the  coke  or  other  matter. 

3.  The   aggregate  of  cell  space  in  one  hundred  volumes  of 
material,  or  percentage  of  cells  by  volume. 

4.  The  volume  of  cells  in  a  given  weight  of  material,  as  cubic 
centimeters  in  100  grams. 

The  loss  in  weight  of  the  material  saturated  with  water,  being 
equal  to  the  volume  of  water  displaced  by  the  mass,  enables  us 
to  determine  the  specific  gravity  of  the  latter;  while  this  loss  in 
weight,  less  the  weight  of  the  water  absorbed  by  the  mass,  gives 
the  true  volume  of  water  displaced  by  its  body,  and  hence  the 
means  of  determining  its  specific  gravity. 

The  division  of  the  amount  of  water  absorbed  by  the  amount 
of  water  displaced  gives  the  amount  of  volume  of  the  cells  in  a 
unit  of  the  material,  and  the  division  of  the  weight  of  the  water 
absorbed  by  the  weight  of  the  dry  mass  gives  the  aggregate  vol- 
ume of  cells  in  a  unit  of  the  mineral. 

Let  a  =  weight  of  dry  material ; 

b  =  weight  of  water  that  it  can  absorb ; 

c=  loss  in  weight,  in  water,  of  saturated  material. 

Then,  c  :  a  =  1,000  :  x  =  apparent  specific  gravity,  or  the 
specific  gravity  of  the  mass. 

c  —  b  :  a  =  1,000  :  x  =  true  specific  gravity,  or  specific  gravity 
of  the  body  of  the  mineral,  water  being  1,000. 

c  :  b  =  100  :  x  =  percentage  by  volume  of  the  cells  in  the 
mineral. 


TREATISE  ON  COKE  357 

a  :  b  =  100  :  x  =  volume  of  cells  in  100  parts  by  weight  of  the 
mineral;  say,  cubic  centimeters  in  100  grams. 

In  coke  determinations,  Messrs.  Mills  and  Rowan,  in  "Chemical 
Technology,"  Philadelphia,  1889,  submit  the  necessity  of  some 
changes  in  the  foregoing  methods,  as  follows: 

"Suitable  specimens  from  20  to  40  grams  in  weight  were  selected 
to  represent  the  average  physical  condition  of  the  coke.  They 
were  thoroughly  brushed  to  remove  any  loosely  adhering  particles 
that  might  fall  off  during  the  experiments  and  thus  vitiate  the 
results,  and  were  weighed  just  as  received;  they  were  dried  at  a 
temperature  of  100°  centigrade  for  1  hour,  cooled  under  the  desic- 
cator, and  weighed,  the  loss  in  weight  representing  the  amount  of 
moisture  found  in  the  specimen  as  received. 

"Great  difficulty  was  experienced  in  thoroughly  filling  the  cells 
with  water,  on  account  of  the  small  adhesion  between  the  surface 
of  the  coke  and  the  water,  but,  after  considerable  experimenting, 
the  following  general  plan  was  adopted. 

"In  filling  porous  substances  generally  with  water,  two  methods 
are  in  use ;  one  to  soak  the  specimens  in  water  for  a  time  and  then 
to  place  them  in  water  under  the  receiver  of  an  air  pump,  and 
exhaust  until  no  more  air  is  given  off;  and  the  other  to  keep  them 
suspended  in  boiling  water  until  the  pores  (cells)  are  filled  with 
water,  as  is  shown  by  their  ceasing  to  gain  in  weight  on  taking 
them  out,  cooling,  and  weighing.  In  this  case  it  was  found  more 
expedient  to  use  a  combination  of  these  two  methods. 

"In  the  determination  of  the  specific  gravity,  there  are  two 
sources  of  variation,  one  inherent  in  all  specific  gravity  determina- 
tions, and  unavoidable,  the  other  accidental  and  in  a  measure 
disappearing  in  the  averages.  The  first  error  is  due  to  the  possible 
presence  of  water-tight  pores,  or  cells,  causing  a  minus  error  in  the 
determinations.  The  other  error  is  due  to  the  possible  presence  in 
a  piece  of  coke  of  a  small  piece  of  slate,  causing  a  plus  error." 

Tests  for  Strength. — The  cubes  of  coke  used  in  determining 
the  cellular  structure  are  dried,  or  others  that  have  not  been  wet 
are  then  used  to  determine  the  capacity  of  the  coke  for  bearing 
furnace  burdens  without  crushing,  in  a  machine  for  testing  the 
compressive  strength  of  materials. 

The  hardness  of  the  body  of  the  coke  is  determined  by  the  usual 
methods;  but  when  great  care  is  required,  the  resistance  of  a  cube  of 
coke  to  abrasion,  under  specific  pressure  and  speed  on  an  emery  wheel 
is  used  to  ascertain  this  important  property  of  hardness  of  body. 

With  the  data  obtained  under  these  methods,  it  is  demonstrated 
that  an  accurate  estimate  can  be  made  of  the  calorific  value  of  the 
coke  for  blast-furnace  purposes,  as  the  following  estimate,  followed 
by  a  blast-furnace  test,  will  show: 

In  October,  1891,  Mr.  J.  H.  Allen,  vice-president  and  general 
manager  of  the  Cumberland  Valley  Colliery  Company,  Pineville, 


358 


TREATISE  ON  COKE 


D  CHEMICAL  PROPERTIES  OF  COKE 

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Beehive  oven  coke. 

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Connellsville,  Standard 
Pineville,  Kentucky..  . 

Kentucky,  sent  a  sample  of  his 
coke  for  examination  and  esti- 
mate of  its  value  as  a  metal- 
lurgical fuel.  The  accompanying 
table  and  report  were  returned 
to  Mr.  Allen. 

Dear  Sir: — In  compliance  with 
your  request  of  September  17,  I  have 
examined  the  sample  of  your  coke 
that  you  forwarded  for  this  purpose. 
Assuming  that  this  sample  of  your 
coke,  submitted  for  chemical  and 
physical  examination,  is  a  fair  aver- 
age of  its  quality,  I  have  had  seven 
physical  tests  made,  giving  the  aver- 
age of  the  seven  in  the  accompany- 
ing table.  In  this  table,  the  Con- 
nellsville coke  is  included  for  purposes 
of  comparison  between  this  and  other 
cokes.  On  general  principles,  coke 
for  metallurgical  uses  should  possess 
hardness  of  body  with  well-developed 
cell  structure  so  as  to  insure  exemp- 
tion from  combustion  in  the  upper 
regions  of  a  blast  furnace,  and  to 
afford  the  utmost  calorific  energy  in 
the  lower  region  of  the  furnace. 
Hardness  of  body  in  coke  prevents 
its  dissolution  by  the  furnace  gases, 
in  a  section  of  the  furnace  where  it 
is  not  only  a  waste  of  fuel,  but 
where  it  disturbs  the  orderly  working 
of  the  furnace.  The  large  cell  devel- 
opment in  coke  assures  its  calorific 
energy  in  combustion. 

The  coke  you  have  submitted 
from  your  Pineville  works  shows 
that  it  has  been  carefully  and  intel- 
ligently treated  in  the  coke  ovens. 
There  are  no  indications  to  show 
where  an  improvement  could  be 
suggested  in  this  respect.  The  coke 
has  the  usual  slender  columnar 
structure  somewhat  peculiar  to  Ken- 
tucky cokes.  It  will  be  seen  in  the 
table  that  the  cellular  structure  of 
this  coke  is  somewhat  below  the 
standard  Connellsville. 

This  slight  physical  defect  is 
compensated,  in  a  great  measure,  for 
blast-furnace  use  by  the  slender  finger 
structure  of  the  coke  as  it  comes 
from  the  coke  ovens.  Its  burden- 
bearing  qualities  are  equal  to  the 
highest  blast  furnaces  now  in  use  or 
likely  to  be  attempted  in  time  to 
come.  The  hardness  of  this  coke  is 
so  near  that  of  the  Connellsville 


TREATISE  ON  COKE 


359 


standard  that  it  is  not  necessary  to  draw  any  special  distinction.  The 
chemical  analysis  shows  that  it  is  a  much  purer  fuel  than  that  of  the 
Connellsville  standard.  The  ash  is  remarkably  low,  only  one-third  of  the 
volume  found  in  the  Connellsville.  As  a  clean  fuel,  it  has  few  if  any  supe- 
riors. It  will  also  be  noted  that  the  exceptionally  low  percentage  of  the 
element  phosphorus  in  this  coke  gives  it  special  adaptability  for  smelting 
Bessemer  pig  iron.  The  sulphur  is  low,  under  that  of  the  standard.  It  will 
be  found  a  very  superior  fuel  for  blast-furnace  purposes,  for  smelting  iron  in 
cupolas,  and  for  all  metallurgical  purposes  in  which  coke  is  used  as  a  fuel. 

JOHN  FULTON,  E.  M. 

Immediately  following  this  report,  a  shipment  of  this  coke  was  for- 
warded to  the  Nashville  Furnace  Company  for  an  actual  test  of  its 
value  in  this  furnace.  The  following  letter  shows  the  result  of  this 
test. 

NASHVILLE,  TENNESSEE,  October  31,  1889. 
MESSRS.  J.  D.  ANDERSON  cfc  Co. 

Gentlemen: — In  reply  to  your  favor  of  this  date,  we  have  to  say  that 
on  the  23d,  24th,  and  26th  inst.,  we  made  a  test  at  our  furnaces  of  the  Cumber- 
land Valley  Colliery  Company's  Pineville  coke.  As  the  coke  was  new  to 
us,  we,  as  a  matter  of  prudence,  charged  light  in  the  beginning,  using  4,000 
pounds  of  ore,  2,100  pounds  of  lime,  and  2,800  pounds  of  coke.  The  furnace 
being  too  hot  on  the  23d,  we  increased  the  ore  to  4,800  pounds.  The  fur- 
nace still  being  too  hot  on  the  24th  inst.,  we  increased  to  5,300  pounds, 
being  the  same  burden  we  had  carried  with  Pocahontas  coke,  with  as  good 
results.  When  we  came  to  understand  the  nature  of  the  Pineville  coke,  we 
produced  as  much  iron  and  a  higher  grade  of  iron  than  we  had  previously  done 
with  other  cokes.  Yours,  etc., 

H.   W.   BUTTORFF, 

President  and  General  Manager. 

J.  H.  HANLEY, 
Superintendent  and  Furnace  Manager. 

Test  for  Resistance  to  Solution  by  C02. — An  additional  test  has 
recently  been  introduced,  in  determining  the  resistance  of  coke  to 
the  dissolving  agency  of  hot  carbonic-acid  gas,  which  proves  the 
relative  hardness  of  body  in  anthracite  and  coke  fuels. 

Average  samples  of  each  kind  of  fuel  are  powdered  and  thor- 
oughly dried.  About  800  cubic  centimeters  are  placed  in  a  test 
tube.  Hot  carbonic-acid  gas  is  passed  over  the  powdered  coke 
during  a  fixed  time.  The  coke  is  carefully  weighed  as  it  is  placed 
in  the  tube,  and  after  it  is  taken  out  the  difference  in  weight  shows 
the  loss  by  dissolution  and  the  relative  hardness  of  body  in  resist- 
ing dissolution  by  this  test. 

TABLE  SHOWING  RESISTANCE  TO  SOLUTION  BY  CO2 


Kind  of  Fuel 

Iff! 

05  <D 

nJO 

1 

Remarks 

^  ^>C   a> 

o  v 

Oj 

^H^  ^ 

W 

Anthracite               

96.0 

4.0 

2.5 

Connellsville  coke  

94.5 

5.5 

3.7 

Coked  in  Otto-Hoffman  ovens 

Connellsville  coke  

91.9 

9.0 

3.0 

Coked  in  beehive  ovens 

Morris  Run  

88.8 

11.2 

2.6 

Coked  in  Semet-Solvay  ovens 

Bennington 

86.1 

13.9 

2.4 

Coked  in  beehive  ovens 

360  TREATISE  ON  COKE 

The  preceding  table  exhibits  some  tests  made  in  this  way,  by 
the  late  Doctor  James  J.  Fronheiser. 

The  percentages  in  the  CO  column  indicate,  approximately, 
the  probable  loss  in  these  fuels  from  softness  of  body. 

The  following  statement  shows  the  ultimate  average  compress- 
ive  strength  of  the  above  fuels,  per  cubic  inch,  without  crushing: 

POUNDS 

Anthracite 3,000 

Connellsville  coke 2,260,  coked  in  Otto-Hoffman  ovens 

Connellsville  coke 1,204,  coked  in  beehive  ovens 

Morris  Run  coke 1,360,  coked  in  Semet-Solvay  ovens 

Bennington  coke 848,  coked  in  beehive  ovens 

From  the  foregoing  data,  it  will  readily  appear,  that  labora- 
tory determinations  of  the  properties  of  these  fuels  will  afford 
very  accurate  results  in  estimating  their  several  calorific  values  in 
metallurgical  operations. 

It  may  be  noted  here  that  in  selecting  the  several  portions  of 
the  coke  for  cutting  into  cubes  for  physical  tests,  that  the  outside, 
inside,  top,  middle,  and  bottom  pieces  have  been  carefully  selected, 
so  as  to  secure  the  true  general  average. 

The  Buffalo  blast-furnace  tests  of  Connellsville,  beehive  coke, 
and  Semet-Solvay  coke,  made  from  Connellsville  coal,  is  interest- 
ing as  exhibiting  the  relative  calorific  energies  of  these  fuels.  The 
work  of  2  days  was  selected,  during  which  the  furnace  was  con- 
sidered to  be  in  equally  favorable  conditions  for  testing  these  fuels, 
1  day  to  each  kind. 

The  following  results  were  obtained:  1895,  May  14,  2,193 
pounds  of  Connellsville  coke  to  1  ton  Bessemer  metal;  1895,  May 
20,  2,400  pounds  of  retort  coke  to  1  ton  Bessemer  metal.  Exhib- 
iting an  increased  heat  value  of  8.21  per  cent,  of  the  former  above 
that  of  the  latter  product. 

Taking  the  cellular  spaces  of  these  fuels,  at  a  general  average 
of  56  per  cent,  in  the  beehive  to  50  per  cent,  in  the  retort,  the 
increased  volume  of  the  former  over  the  latter  is  10.7  per  cent., 
exhibiting  a  slight  increase  in  theoretic  heat  value  over  the  blast- 
furnace tests. 


CHAPTER  IX 


THE  LOCATING  OF  PLANTS  FOR  THE  MANUFACTURE 

OF  COKE 

Preliminary  Considerations, — In  former  chapters,  the  methods 
of  preparing  coal  for  making  coke  with  the  ovens  adapted  for 
producing  the  best  metallurgical  fuels  have  been  considered.  It 
is  evident  that  the  first  important  effort  that  should  elicit  the  full 
attention  of  the  manufacturer  of  coke  is  to  produce  it  of  a  uniform 
first-class  quality.  This  will  assure  his  product  a  ready  market, 
and  secure  his  men  continuous  work  at  the  ovens  in  the  usual 
times  of  uninterrupted  business.  The  second  effort  relates  to  a 
consideration  of  how,  in  the  economies  of  location  of  a  coking  plant, 
full  profit  can  be  secured  to  the  manufacturer. 

It  is  assumed  that  wise  coke  makers  do  not  enter  this  branch 
of  industry  alone  in  the  interest  of  science,  but  reasonably  expect 
moderate  compensation  for  capital  invested,  time  devoted  to  the 
industry,  and  compensation  for  the  exhausting  coal. 

In  order  to  secure  this  second  condition,  as  far  as  it  can  be 
controlled  by  the  location  of  the  coking  plant,  it  will  readily  appear 
that  this  element,  in  affording  economy  in  the  coking  operations, 
requires  careful  consideration.  Without  in  the  least  under- 
valuing the  good  practical  judgment  of  the  coke  manufacturer, 
it  may  be  submitted  that  it  will  conduce  to  economy  to  secure 
the  professional  service  of  an  expert  engineer  in  the  work  of  loca- 
ting the  coke-oven  plant.  Sometimes  a  few  dollars  are  saved  by 
not  employing  a  competent  engineer,  with  the  result  that  in  the 
end  a  great  many  are  wasted. 

In  common  with  modern  progress  in  the  economical  location  of 
industrial  plants,  the  arrangements  of  the  coking  plant  and  its 
source  of  coal  supply  should  receive  the  benefits  of  recent  improve- 
ments in  these  respects.  The  principles  that  evidently  should 
govern  the  location  of  a  coking  plant  consist  in  affording  full 
facilities  in  the  performance  of  all  the  work  in  the  manufacture 
of  coke  with  its  resultant  economizing  in  this  labor.  The  location, 
however,  is  governed,  in  part,  by  the  topography  of  the  locality 
in  which  it  is  designed  to  establish  the  work.  The  general  plan 
will  require  to  conform  to  these  conditions. 

It  may  be  noted  that  the  site  for  the  coke  ovens  is  generally 
determined  by  the  location  of  the  coal  mine  opened  for  the  supply 

361 


362 


TREATISE  ON  COKE 


of  coal  to  the  ovens.  A  little  preliminary  careful  attention  in  the 
location  of  the  coal  mine  with  a  view  of  affording  the  best  possible 
ground  for  the  ovens  would  conduce  to  economies  in  both. 

In  the  location  of  plants  of  coke  ovens  of  one  or  more  banks, 
the  gradients  of  the  larry  tracks  on  the  ovens,  as  well  as  the  tracks 
of  the  railroad  sidings,  should  afford  descending  grades  of  at  least 
1  per  cent.,  so  as  to  secure  the  movements  of  the  larries  and  rail- 
road cars  by  gravity,  thus  avoiding  mainly  the  use  of  locomotives 
or  horse  power  in  these  operations. 


FIG.  1.    ELECTRIC  COKE  LARRY 

It  may  be  noted  here  that  electrical  power  in  moving  the  coal- 
charging  larries  along  banks  of  coke  ovens  is  rapidly  superseding 
horse  or  mule  power.  At  this  writing  many  of  the  large  plants 
of  beehive  or  retort  coke  ovens  have  this  power  in  full  operation, 
securing  rapid  movement  of  the  larries  and  quick  charging  of  the 
coke  ovens  with  coal  after  the  coke  has  been  drawn  out,  increasing 
the  time  of  coking  in  the  oven  and  securing  a  more  complete 
product  of  coke. 

Fig.  1  shows  an  electrically  operated  larry.  The  sheet-steel 
box  hopper  a  is  about  8  feet  6  inches  square  and  2  feet  6  inches 
deep.  The  bottom  of  the  hopper  tapers  on  all  four  sides  as  shown. 
The  larry  shown  has  but  one  discharge  chute  b  and  is  used  for 


TREATISE  ON  COKE  363 

bank  ovens  that  are  charged  from  one  side  of  the  larry.  If  the 
larry  track  is  situated  between  two  blocks  of  ovens,  there  are  two 
discharge  chutes,  one  on  each  side  of  the  larry.  The  outer  part 
of  the  chute  c  is  hinged  to  the  fixed  part  b  so  that  it  may  be  drawn 
up  by  means  of  the  chain  d' and  wheel  e  and  thus  stop  the  coal 
from  running  down  the  chute.  The  larry  hopper  and  chutes  are 
supported  by  a  metal  framework  that  rests  upon  four  wheels, 
each  pair  of  wheels  being  provided  with  springs  in  connection  with 
the  journal-boxes.  The  larry  shown  is  electrically  operated  by  a 
motor  /  that  transmits  the  motion  to  the  axle  g  by  means  of  the 
gearing  h,  i.  The  current  is  taken  from  overhead  wire  through 
the  trolley  pole  /. 

The  equipment  of  many  larries  consists  of  a  standard  railway 
motor  of  the  enclosed  type  mounted  on  one  of  the  axles.  The 
motor,  controller,  and  trolley  may  be  applied  to  larries  at  present 
drawn  by  animal  power,  it  being  unnecessary  to  design  a  special 
larry  'adapted  for  the  electrical  equipment.  The  control  is  so 
perfect  that  when  about  to  discharge  its  load  into  the  ovens,  the 
larry  may  be  moved  in  either  direction  literally  "an  inch  at  a 
time,"  and  a  much  higher  speed  is  possible  than  with  horses  or 
mules.  The  result  is  a  surprising  saving  in  time  in  hauling  from 
and  returning  to  the  tipple,  and  in  discharging  the  coal  at* the 
ovens.  The  trolley  or  third-rail  system,  preferably  the  latter, 
may  be  used  to  convey  the  power  to  the  motor,  and  the  approaches 
to  the  ovens  may  be  much  more  cheaply  constructed,  as  it  is 
unnecessary  to  provide  a  path  for  the  horses  or  mules. 

One  electrically  equipped  larry  with  its  operator  will  easily 
do  the  work  of  two  mule  larries  with  their  drivers,  and  when  the 
conditions  permit,  the  electric  larry  may  supply  the  motive  power 
for  other  larries,  which,  operated  as  trailers,  may  be  dropped  at 
the  proper  places,  having  been  loaded  at  the  tipple,  and  picked  up 
on  the  return,  in  the  meantime  having  discharged  their  loads  into 
the  ovens.  The  increased  adoption  of  electric  mining  locomotives 
and  electric .  motors  for  driving  pumps,  hoists,  car  conveyers, 
blowers,  etc.  should  be  considered  in  connection  with  the  instal- 
lation of  a  dynamo  for  the  operation  of  coke  larries,  but  even  if 
the  conditions  are  such  as  to  debar  other  applications  of  electricity, 
the  investment  will  show  a  very  good  return.  At  many  mines, 
generating  plants  are  already  installed,  in  which  cases  the  addi- 
tional investment  would  be  very  small  indeed,  and  the  saving  in 
cost  of  operation  would  soon  pay  for  the  electrical  equipment  of 
the  larry. 

Attention  should  also  be  given  to  facilitating  the  disposal  of 
the  waste  products  of  ashes  and  coke  dust,  as  these  elements 
accumulate  largely,  even  in  a  plant  of  moderate  size.  The  water 
supply  should  be  pure  and  the  quantity  ample  at  all  seasons  of 
the  year,  with  a  medium  pressure  to  afford  a  full  supply  of  water 
and  prevent  wear  to  the  hose  or  injury  to  the  brickwork  of  the 


364 


TREATISE  ON  COKE 


ovens  by  an  overpressure  in  the  water  discharge.  In  retort  coke 
ovens,  where  the  coke  is  cooled  on  the  outside  of  the  oven,  the 
regulation  of  pressure  in  the  water  supply  would  only  refer  to  the 
wear  on  the  connecting  hose. 

The  following  plans  of  the  location  of  beehive  and  retort-coke- 
oven  plants  are  given  to  illustrate  the  salient  elements  to  be 
secured  in  laying  out  new  works.  They  are  not  designed  to  convey 
the  idea  of  perfectness,  put  to  indicate  the  means  of  doing  the  best 
with  the  topography  of  the  locality  in  which  the  ovens  are  to  be  built. 

The  Morrell  plant  in  the  Connellsville  region  illustrates  the 
methods  of  locating  a  group  of  four  banks  of  coke  ovens,  each 
bank  containing  100  beehive  ovens.  This  plant  was  constructed  in 
1880  by  the  Cambria  Iron  Company,  of  Johnstown,  Pennsylvania. 

Fig.  2  shows  the  general  location  of  ovens,  tipples,  bins,  and 


FIG.  2.     MORRELL  COKE  WORKS,  CAMBRIA  IRON  Co. 

a,  Morrell  slope;  b,  man  way;  c,  car  shop;  d,  stable;  e,  office;  f,  coal  pile;  g,  air-shaft; 
h,  boiler  house;  *',  engine  house;  /,  blacksmith  shop;  k,  400  coke-ovens;  s,  railroad  sidings. 

railroad  sidings.  In  locating  at  this  place,  it  was  found  necessary 
to  open  the  mine  by  a  slope  a  driven  down  the  coal  seam,  which 
is  8  feet  thick  and  has  an  inclination  or  dip  of  5|°  to  the  north- 
west. The  coal  is  raised  by  extending  the  plane  of  the  slope  until 
it  attains  an  elevation  of  about  40  feet  above  the  level  of  the  tops 
of  the  coke  ovens. 

The  beehive  coke  ovens  k  are  located  in  four  parallel  banks, 
each  of  which  is  700  feet  long.  Each  bank  of  ovens  has  its  flank- 
ing wharves.  These  wharves  afford  ample  space  for  drawing  the 
coke  from  the  ovens  and  loading  it  on  railroad  cars.  The  wharves 
are  25  feet  wide  and  7  feet  high. 

The  ground  on  which  these  ovens  have  been  located  has  a 
gentle  inclination  eastwards,  with  sufficient  descent  to  enable  rail- 
road cars  and  charging  larries  to  be  moved  down  grade  by  gravity. 
The  railroad  tracks  have  been  arranged  so  as  to  afford  ample  room 
for  receiving  empty  coke  cars  at  the  upper  or  west  end  of  ovens, 
and  to  permit  the  shifting  of  the  loaded  cars  below  the  ovens. 


TREATISE  ON  COKE 


365 


No  locomotive  power  is  used  at  this  plant.  A  man  shifts  the 
railroad  cars  from  the  upper  sidings  and  places  them  at  points 
along  the  wharves  for  loading  with  coke.  When  loaded  they  are 
shifted  down  to  the"  sidings  below  the  lower 
end  of  the  coke  ovens. 

The  coal  bins,  Fig.  3,  are  constructed 
of  heavy  framed  timbers,  with  white-oak 
plank  lining.  Each  bin  holds  from  300  to 
400  tons  of  coal.  There  is  one  bin,  with  a 
double  line  of  hoppers,  to  each  bank  of 
100  ovens.  These  coal-storage  bins  afford 
ample  supplies,  so  that  the  ovens  can  be 
charged  promptly  after  the  coke  has  been 
drawn  out. 

The  coal  is  brought  from  the  mine  to 
the  platform  along  the  front  of  these  bins, 
and  is  there  dumped  into  any  of  the  com- 
partments in  the  usual  manner.  Horses 
or  mules  are  used  in  the  movements  of 
the  mine  cars  from  the  head  of  the  slope 
plane  to  these  bins.  This  arrangement  has 


FIG.  3.     COAL-STORAGE  BIN 


been  found  to  work  with  economy. 
A  device  consisting  of  an  endless 
wire  rope,  with  grip,  might  be 
used  with  economy  for  this  work 
of  delivering  loaded  cars  and 
returning  the  empty  ones  to  head 
of  plane ;  or,  better  still,  electrical 
power  might  be  employed. 

The  water  supply  comes  from 
the  Youghiogheny  River.  It  is 
pumped  to  an  elevation  affording 
sufficient  head  to  supply  the 
ovens  and  the  tenement  houses 
at  this  and  the  Wheeler  plants. 

No.  3  Plant,  H.  C.  Frick  Coke 
Company. — Fig.   4  will  convey  a 
correct  conception  of  the  general 
plan    of    location    of    the    large 
coking  plant  constructed  by  the 
a,  Fan  and  air-shaft;  6,  shops;  c,  coal  bins;  Leiscnring    interests     under    the 
h'  vuiige*'  engine;  f>  boilers;  g' coke  ovens;  name   of   the    Connellsville   Coke 

and   Coal   Company.     It   is  now 
owned  and  operated  by  the  H.  C.  Frick  Coke  Company. 

It  will  be  seen  by  Fig.  4  that  these  ovens  g,  g  were  located  in 
two  curved  wings  on  either  side  of  the  coal  bins  c  and  shaft  d,  up 
the  gentle  valley  threaded  by  the  Pennsylvania  railroad  and  the 


FIG.  4.     PLAN  OP  H.  C.  FRICK  COKE 
COMPANY'S  No.  3  COKE  PLANT 


366 


TREATISE  ON  COKE 


sidings  for  this  large  plant  of  coke  ovens.  The  ovens  are  charged 
in  the  usual  way,  a  small  locomotive  being  used  in  handling  the 
coal  larries  to  the  several  banks  of  ovens.  This  secures  com- 
mendable despatch  in  this  department  of  the  work.  The  larry 
tracks  are  between  the  double  rows  of  ovens.  The  side  chutes  to 
these  charging  larries  can  be  seen  in  Fig.  5. 

The  wharves  are  ample,  and  the  whole  arrangement,  for  each 
division  of  labor,  very  complete. 

The  elevation,  Fig.  5,  showing  details  of  head-house  and  bins 
affords  very  complete  details  of  these  constructions  for  a  central 
supply  of  coal  for  charging  the  ovens. 


FIG.  5.     HEAD-HOUSE  AND  BINS,  H.  C.  PRICK  COAL  COMPANY'S  No.  3  COKE  PLANT 

The  only  suggestion  that  occurs  on  the  line  of  security  against 
fire  at  this  plant  is  that  the  head-house  over  the  deep  shaft  would 
be  safer  from  the  danger  of  fire  if  constructed  mainly  of  iron. 

The  burning  of  a  head-house  causes  immediate  stoppage  of 
the  coke  works,  with  interruption  to  coke  shipments  and  serious 
financial  loss. 

Oliver  Plant. — Messrs.  Wilkins  and  Davison,  Engineers,  Pitts- 
burg,  Pennsylvania,  have  kindly  furnished  plans,  Fig.  6,  of  the  two 
very  complete  coking  plants  of  the  Messrs.  Oliver,  of  Pittsburg, 
located  near  Uniontown,  in  the  Connellsville  coke  region. 

The  whole  arrangement  of  these  plants  with  their  coal  mines 
and  bin  storage  supplies  affords  excellent  examples  of  wise  har- 
monies in  securing  economical  and  safe  conditions  to  both  the 
mines  and  coke  ovens. 

The  following  able  paper  by  Mr.  Fred  C.  Keighley,  general 
superintendent  of  the  Oliver  Coke  Works,  will  afford  much  valuable 
matter  on  the  location,  size  of  plant,  with  an  outlook  as  to  the 
requirements  of  the  works  to  supply  special  markets  and  other 


367 


368 


TREATISE  ON  COKE 


related  conditions.  It  also  affords  many  practical  suggestions  on 
these  elementary  requirements  in  the  order  of  economy  and  facility 
of  operations. 

Plant  No.  1  consists  of  300  beehive  ovens,  in  two  slightly  curved 
lines,  to  conform  to  the  topography  of  the  ground,  securing  desir- 
able gradients  for  railroad  sidings  and  larry  tracks.  One  of  these 
banks  of  coke  ovens  is  located  in  a  line  of  single  ovens  1,400  feet 
long,  containing  100  ovens.  The  second  line,  of  about  the  same 
length,  consists  of  a  bank  of  a  double  row  of  ovens,  containing 
200  ovens. 

The  railroad  tracks  and  sidings  are  ample  and  well  located  to 
afford  the  necessary  facilities  for  handling  the  output  of  coke. 


FIG.  7.     COKE  OVEN  PLANT  (300  OVENS).     PLANT  No.  1,  OLIVER  COKE  WORKS,  REDSTONE 

JUNCTION,  PENNSYLVANIA 

The  ovens  and  railroad  tracks  are  on  gradients  of  1  foot  per  100 
feet,  descending  with  the  tonnage.  The  ovens  are  12  feet  3  inches 
in  diameter.  This  plant  was  completed  early  in  1892;  since  that 
time  it  has  been  increased  to  1,208  ovens. 

The  locations  of  the  shaft,  engine  house,  and  coal  bin  can  be 
seen  on  the  plan.  They  were  located  to  secure  the  utmost  economy 
in  the  manufacture  of  coke.  Fig.  7  shows  some  of  the  ovens  in 
process  of  building. 

Plant  No.  2  has  been  located  in  three  double  banks  of  coke 
ovens.  Each  bank  is  825  feet  long  and  contains  120  coke  ovens, 
making  in  all  at  this  plant  360  ovens.  The  compact  location  of 
these  ovens,  with  the  close  relations  of  shaft  and  coal  bins  to  the 
ovens  evidence  careful  work  in  the  plans. 


TREATISE  ON  COKE 


369 


The  railroad  sidings  are  well  located  for  convenience.  The 
railroad  cars  require  some  extra  handling  at  this  plant,  as  the 
railroad  connections  are  confined  to  one  end  of  the  ovens. 

At  these  works,  the  shafts  to  the  coal  are  about  415  feet  deep. 

Danger  from  fire  has  been  guarded  against  at  these  works 
by  constructing  the  head-frames  of  shafts  of  steel  covered  with 
corrugated  iron,  Figs.  8  and  10.  The  coal-storage  bins  have  been 
constructed  with  similar  materials  and  the  engine  houses  of  brick 
with  iron  roofs.  It  is  claimed  that  these  fireproof  structures  are 
the  first  of  their  kind  introduced  into  the  Connellsville  coke  region. 
This  introduction,  in  the  lines  of  safety  to  life  and  true  economy 
in  assuring  continuous  work,  is  very  commendable.  The  water 
supply  is  secured  from  the  Youghiogheny  River,  10  miles  distant. 


COKE  MAKING  FOR  PROFIT* 


A  plant  of  more  than  300  coke  ovens  becomes  unwieldy;  and 
when  the  ovens  are  less  in  number  than  300,  the  fixed  charges  are 
apt  to  be  high.  A  man  can  manage  two  300-oven  plants,  if  not 


FIG.  8.     HEAD-FRAME  AND  ENGINE  HOUSE,  PLANT  No.  1,  OLIVER  COKE  WORKS, 
REDSTONE  JUNCTION,  PENNSYLVANIA 

too  far  apart,  with  more  ease  than  one  600-oven  plant,  and  it 
takes  as  many  officials  to  operate  a  600-oven  plant  as  to  operate 
two  300-oven  plants.  So,  if  a  large  number  of  ovens  is  desired, 
the  best  plan  is  to  divide  them,  as  nearly  as  practicable,  into 
300-oven  plants.  This  is  not  only  my  view  of  the  matter,  but 
the  view  of  the  more  experienced  coke  men  of  the  Connellsville 

*Fred  C.  Keighley,  in  American  Manufacturer. 


370 


TREATISE  ON  COKE 


TREATISE  ON  COKE  371 

coke  region.  So,  in  what  I  write  hereafter,  I  shall  make  my  obser- 
vations and  suggestions  mainly  with  reference  to  a  plant  of  that 
magnitude.  However,  there  are  many  people  who  will  not,  or 
cannot,  build  a  plant  of  300  ovens,  and  they  will  naturally  ask  how 
they  are  to  determine  how  many  ovens  to  build.  This  is  a  some- 
what difficult '  matter  to  decide,  as  there  are  many  things  to  con- 
sider; yet  there  are  certain  conditions  that  in  a  degree  indicate 
what  is  to  be  done.  For  instance,  if  the  manufacture  of  coke  for 
the  blast-furnace  trade  is  contemplated,  then  the  extent  of  that 
kind  of  trade  to  be  had  will  fix  the  number  of  ovens  to  be  built. 

Modern  blast  furnaces  consume  all  the  way  from  300  to  600  tons 
of  coke  per  day,  and  as  many  furnace  men  object  to  the  use  of 
mixed  coke,  owing  to  its  interfering  with  regular  or  uniform  work, 
to  build  less  than  sufficient  ovens  to  run  one  furnace  would  cer- 
tainly be  fatal  to  the  success  of  the  venture.  Generally  speaking, 
12-foot  beehive  coke  ovens  will  yield  2  tons  of  coke  per  oven  per 
day;  so  that  a  blast  furnace  of  300  tons  of  coke  per  day  capacity, 
will  require  2,100  tons  of  coke  per  week  of  7  days.  A  coke-oven 
week  is  but  6  days;  therefore,  the  quantity  required  from  the  ovens 
will  be  350  tons  per  day;  this  divided  by  2  will  give  us  175  coke 
ovens,  the  number  required.  A  two  300-ton  furnace  capacity 
plant  would  require  350  ovens,  and  so  on.  If  foundry  trade  were 
to  be  supplied,  instead  of  furnace  trade,  the  number  of  ovens 
required  would  be  determined  in  an  altogether  different  manner; 
and  I  know  of  no  better  or  safer  way  of  determining  it  than  by 
the  coal  acreage  owned  or  controlled  by  the  prospective  coke 
operators. 

An  8-foot  seam  of  Connellsville  coal  will  yield  fully  12,000  tons 
of  coal  per  acre,  if  free  from  faults  and  skilfully  mined,  and  this 
in  turn,  if  properly  manipulated,  will  yield  8,000  tons  of  coke. 
Taking  600  tons  as  the  work  of  a  12-foot  beehive  oven  for  1  year, 
an  acre  of  coal  will  keep  one  coke  oven  running  steadily  for  13  J 
years — allowing  for  dull  trade,  strikes,  car  shortages,  and  repairs, 
we  might  safely  put  it  15  years. 

If  the  coal  to  be  operated  is  drift  coal  and  comparatively  cheap 
to  develop  and  equip,  15  years  will  be  a  safe  life  for  the  plant; 
but  should  the  coal  be  below  water  level,  necessitating  the  instal- 
ment of  costly  machinery  and  pumps,  and  the  sinking  expenses 
be  heavy,  then  30  years  will  be  none  too  great  a  period  to  allow  to 
get  out  all  there  is  in  the  equipment.  For  instance,  a  property  of 
150  acres  of  drift  coal  will  require  150  coke  ovens  to  make  what  I 
term  a  fairly  well-proportioned  plant;  but  a  slope  or  shaft  coal 
property  of  over  100  feet  and  up  to  200  feet  in  perpendicular 
depth,  to  get  the  best  attainable  results,  should  be  of  such  acreage 
as  to  sustain  at  least  200  coke  ovens  for  30  years.  A  200-oven  plant 
on  such  a  basis  will  require  at  least  400  acres  of  coal.  Deeper 
coal  would  require  more  coke  ovens  and  a  correspondingly  greater 
acreage  to  make  it  a  well-balanced  venture.  Take  the  following 


372 


TREATISE  ON  COKE 


FIG.  10.     HEAD-FRAME  AND  COAL  BIN  AT  OLIVER  No.  3  PLANT 


Q 

SOS 


17303— ix 


FIG.  11.     PLAN  OF  AMERICAN  COAL  AND  COK 


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MPANY'S  PI-ANT  AT  EDENBORN,  PENNSYLVANIA 


I  *  oA 


TREATISE  ON  COKE  373 

figures  as  factors :  One  coke  oven  yields  600  tons  of  coke  per  year. 
One  acre  of  8-foot  Connellsville  coal  yields  12,000  tons  of  coal; 
12,000  tons  of  coal  makes  8,000  tons  of  coke.  One  acre  of  8-foot 
coal  will  run  one  oven  15  years.  Life  of  a  drift  plant  is  15  years; 
life  of  a  100-foot  sinking,  30  years.  One  acre  of  coal  for  each  oven 
at  a  drift  plant.  Two  acres  of  coal  for  each  oven  at  a  100-  to  200- 
foot  depth.  Twice  as  many  coke  ovens  on  a  200-  to  400-foot 
depth  as  on  a  100-  to  200-foot  depth,  and  a  correspondingly  increased 
acreage.  In  very  large  tracts  of  coal  land,  a  correspondingly 
large  number  of  ovens  in  plants  of  300  ovens  to  each  establishment. 

With  this  data  as  a  basis  for  calculation,  any  one  of  ordinary 
ability  should  be  able  to  determine  the  number  of  ovens  required 
on  a  given  acreage,  or  the  acreage  required  for  a  given  number  of 
ovens.  Of  course,  the  kind  of  trade  expected  must  not  be  over- 
looked in  making  up  the  verdict. 

Small  coke  plants  are  generally  arranged  on  a  single  line  of  bank 
ovens,  but  the  larger  plants  are  made  up  of  several  rows  of  bank 
and  block  ovens,  in  order  to  secure  compactness,  etc.  The  arrange- 
ment of  the  ovens  is  generally  governed  by  the  location  that  is 
available.  There  are  very  few  natural  oven  locations,  and  often, 
even  when  a  good  oven  location  is  found,  it  cannot  be  used  because 
it  does  not  also  afford  a  good  coal  mine  site,  or  the  grades  are 
such  that  it  cannot  be  reached  by  railroad  with  a  profitable  grade. 
It  would  be  out  of  the  question  to  lay  down  any  rules  as  to  the 
arrangement  of  the  ovens;  so  what  I  have  to  say  relative  to  the 
location  of  the  ovens,  etc.,  must  be  taken  in  a  general  way  and 
with  due  consideration. 

Beehive  bank  ovens  when  located  parallel  with  or  to  moder- 
ately rising  ground  where  the  rock  does  not  crop  out  above  the 
floor  or  seat  of  the  contemplated  oven,  and  the  soil  is  of  the  proper 
character  and  solidity  and  can  be  well  drained,  make  the  best 
and  cheapest  of  all  beehive-oven  locations — best,  because  the  oven 
can  be  located  on  naturally  solid  ground,  affording  a  firm  founda- 
tion at  small  cost,  and  the  ground  rising  behind  them  affords  not 
only  a  storage  battery  for  heat,  but  also  allows  the  oven  to  expand 
backwards  instead  of  forwards,  and  thus  relieves  the  oven  and 
retaining  walls  from  excessive  strains.  Another  advantage  with 
such  a  location  is  that  all  the  ovens  face  the  pure  air,  if  all  in  one 
string,  which  is  quite  an  advantage,  as  coke  ovens  that  face  the 
air  always  make  more  and,  unless  in  stormy  weather,  brighter  coke. 

Bank  ovens  are  the  cheapest  to  build,  for  the  reason  that  the 
side  cut  for  the  ovens  also  makes  the  filling  for  the  coke  yard,  or 
wharf,  while  the  dirt  for  filling  around  the  ovens  can  be  easily  and 
cheaply  obtained  from  the  rising  ground  behind;  however,  I  would 
not  advise  that  the  whole  of  the  300  ovens  be  located  on  a  single 
line,  for  the  following  reasons,  viz.:  First,  because  it  would  not  be 
the  most  economical  way  of  charging  the  ovens,  owing  to  the  long 
distance  to  be  traveled  over;  second,  the  long  distance  traveled 


8* 

*jj 

2£ 

J    y 


1  1 


II 


ffi.S 


374 


TREATISE  ON  COKE  375 

over  would  necessitate  an  increase  of  speed  for  the  charging 
equipment,  which,  in  turn,  would  not  only  cause  excessive  vibra- 
tion, which  would  shorten  the  life  of  the  oven,  but  would  also 
increase  liability  to  accident,  excessive  strains  to  the  larry  tracks, 
and  more  wear  and  tear  to  the  equipment;  third,  the  wheel  on  the 
coke  yard  would  be  longer  than  desirable  for  the  coke  drawers; 
and  fourth,  the  length  of  the  larry  tracks  on  the  ovens,  and  the 
length  of  the  sidings  for  the  railroad  cars  would  be  very  much 
greater  than  desirable,  convenient,  or  economical,  and  would  fur- 
ther necessitate  many  cuts  or  breaks  in  the  ovens  for  ways  for 
ash  carts,  etc.  In  view  of  the  above  important  factors,  the  plant, 
if  all  bank  ovens,  should  consist  of  two  rows  of  ovens  of  150  each, 
the  said  rows  facing  each  other,  with  the  railroad  siding  running 
down  between  the  respective  coke  yards. 

American  Coke  Company's  Plant. — The  coking  plant  of  the 
American  Coke  Company,  Fig.  11,  is  situated  at  the  Edenborn 
mine  in  Fayette  County,  Pennsylvania,  in  the  Connellsville  region. 
It  consists  of  a  plant  of  500  beehive  coke  ovens,  arranged  in  four 
parallel  banks  or  batteries,  with  wharves,  railroad  sidings,  reser- 
voir containing  ample  supplies  of  water,  and  all  necessary  appli- 
ances for  the  successful  working  of  this  plant. 

The  dwelling  houses,  as  shown  on  this  plan,  have  been  neatly 
finished,  affording  comfortable  homes  to  the  miners,  coke  drawers, 
and  other  workmen.  The  whole  arrangement  of  the  several  parts 
affords  evidence  of  a  carefully  considered  plan,  securing  harmony 
of  its  parts  and  economy  in  all  its  operations. 

The  Hostetter  Connellsville  Coke  Company's  works  consist  of 
two  coke  plants,  the  Whitney  and  Lippincott,  located  in  the  north- 
ern section  of  the  Connellsville  field,  about  £  mile  apart,  on  the 
Latrobe  branch  of  the  main  line  of  the  Pennsylvania  Railroad. 

Both  these  works  have  been  located  in  little  valleys  on  small 
streams,  tributaries  of  Nine  Mile  and  Loyalhanna  creeks.  They 
are  very  nearly  alike  in  their  plans  of  location  and  number  of  coke 
ovens.  The  method  of  location  of  the  Lippincott  plant,  Fig.  12, 
will  serve  to  illustrate  the  general  plan  of  both  these  works.  It 
has  not  been  considered  necessary  to  add  the  plan  of  the  location 
of  the  Whitney  works. 

The  Lippincott  coke  plant  consists  of  305  beehive  coke  ovens, 
which  are  12  feet  in  diameter  and  7  feet  high  to  crown  of  the  dome. 
The  ovens  have  been  located  in  two  lines,  along  the  south  bank 
of  the  Nine  Mile  Run,  conforming  in  their  alinement  with  the  con- 
tour of  the  ground  at  this  place.  The  northern  line  of  ovens  is 
composed  of  a  bank  of  a  double  row  of  ovens;  the  southern  bank 
consists  of  a  single  line  of  ovens. 

The  plan,  Fig.  12,  exhibits  the  arrangement  of  the  railroad 
tracks  and  sidings  for  the  supply  of  coke  cars  for  this  trade.  Ample 


376  TREATISE  ON  COKE 

room  has  been  provided  for  storing  empty  coke  cars  at  the  upper,  or 
west,  end  of  the  plant,  with  full  space  at  the  lower,  or  east,  end  for 
making  up  trains  of  loaded  coke  cars  for  transportation  to  market. 

The  coal  cars  are  drawn  up  the  slope  from  the  mine  by  the 
winding  engine  and  placed  on  the  long  coal  bin,  where  they  are 
unloaded  rapidly  into  the  hoppers  underneath.  The  larries  for 
charging  the  coke  ovens  are  loaded  under  these  hoppers. 

The  mine  cars  are  not  unhitched  from  the  wire  haulage  cable, 
but  are  unloaded  into  this  long  bin  by  opening  the  bottom  slides 
in  these  coal  cars.  A  train  of  these  loaded  mine  cars  consists  of 
ten  cars,  containing  45  bushels  in  each  car,  nearly  2  tons  of  coal. 
Immediately  on  their  being  unloaded,  they  are  quickly  lowered 
into  the  mine  and  unhitched  from  the  cable,  which  is  then  hitched 
to  a  loaded  train  of  cars. 

The  larries  for  charging  the  coke  ovens  are  handled  by  a  7-ton 
locomotive  operated  on  standard-gauge  tracks.  The  gradients 
of  railroad  and  larry  tracks  descend  eastward,  affording  nearly 
balanced  gravity  lines  for  these  operations. 

The  office  and  store  is  located  at  the  west  end  of  the  works, 
where  the  incoming  and  outgoing  cars  pass. 

Arrangements  have  been  made  at  both  plants  for  shipping 
coal  when  found  necessary  to  do  so. 

The  slopes  into  the  mines  are  2,600  to  2,800  feet  long.  They 
have  been  driven  in  the  large  coal  seam,  which  has  here  an  incli- 
nation westwards  of  6^  feet  per  100  feet. 

These  works  were  constructed  during  the  years  1889-90,  under 
the  plans  and  supervision  of  Mr.  John  McFayden,  the  general 
manager  of  the  company. 

When  in  full  operation,  these  works  can  produce  about  1,200 
tons  of  coke  per  day.  The  main  effort  in  these  locations  was  to 
reduce  the  cost  of  the  labor  of  making  coke  to  a  minimum.  It  is 
evident  that  this  has  been  secured  as  far  as  the  plan  of  extended 
oven  lines  will  permit.  It  is  worthy  of  future  consideration,  in 
locating  coke  ovens,  whether  more  compact  lines,  like  those  at 
Morrell  and  Oliver  No.  2,  will  afford  more  labor  economy  in  the 
section  of  the  work  in  charging  the  ovens. 

The  Joseph  Wharton  coke  plant.  Fig.  13,  illustrates  the  general 
plan  of  the  Wharton  Coke  Works,  situated  at  Coral  Station  on  the 
Indiana  branch  of  the  Pennsylvania  Railroad,  in  Indiana  County, 
Pennsylvania.  It  consists  of  300  modern  beehive  coke  ovens, 
located  in  two  curved  sections  on  either  slope  of  the  valley  of  a 
little  stream,  a  tributary  to  the  large  Two  Lick  Creek,  securing 
advantageous  gradients  for  the  coke  ovens,  as  well  as  for  the  rail- 
road sidings  and  larry  service.  The  water  reservoir  is  located  in 
the  gentle  valley  of  this  small  stream,  and  is  of  liberal  dimensions 
to  afford  at  all  times  an  ample  supply  of  water  for  all  uses  at 
their  works.  The  water  is  mainly  pumped  from  the  nearby  Two 
Lick  Creek. 


xi  --f.or.-r 


17303— ix 


FIG.  13.     PLAN  OP  JOSEPH  WHARTON  C< 


'  .ANT  AT  CORAL,  INDIANA  COUNTY,  PENNSYLVANIA 


TREATISE  ON  COKE 


377 


The  mine  from  which  the  coal  is  obtained  is  shown  on  this 
plan,  with  its  main  workings,  now  being  rapidly  extended  to  meet 
the  daily  needs,  which,  when  all  the  ovens  are  in  blast,  will  be  1,100 
to  1,200  tons  per  day.  The  coal  lands  of  this  plant  consist  of 
3,000  to  4,000  acres,  containing  all  the  beds  of  the  lower  coal 
measures,  in  the  aggregate  about  19  feet  of  coal.  The  mine  works 
are  in  the  upper  Freeport  coal  bed  (E),  here  5  feet  9  inches  thick 
with  a  slate  parting. 

The  coal  is  broken  to  small  sizes  and  washed  in  preparation 
for  coking.  The  coal  washer  is  of  the  recent  design  of  Stein  and 
Boericke,  of  Primos,  Delaware  County,  Pennsylvania,  having  ample 


FIG.  14.     COAL-STORAGE  RECEIVER 

capacity  to  meet  the  coke-oven  supply.  The  broken  coal  is  not 
classified,  but  is  treated  in  three  continuous  washer  pans,  the  tailings 
receiving  an  additional  cleaning  under  conditions  to  meet  its  needs. 

The  washed  coal  is  elevated  into  a  large  coal-storage  receiver, 
Fig.  14,  where  it  is  allowed  sufficient  time  to  part  with  its  water. 
The  receiver  holds  about  3,000  tons  of  washed  coal  for  the  ovens. 
As  only  about  1,100  tons  per  day  are  required  for  charging  the 
ovens,  it  will  be  seen  that  the  coal  has  over  60  hours  in  which  to 
dry,  prior  to  its  being  charged  into  the  ovens. 

Fig.  14  will  exhibit  the  general  arrangement  of  the  coal-storage 
receiver,  with  the  arrangements  for  lifting  the  coal  and  loading 
it  into  larries. 


378 


TREATISE  ON  COKE 


±1 


Exhausting 

and 

Condensing 
Apparatus 


17303— ix 


FIG.  16.     ARRANGEMENT  OF  < 

a,  Coal  dump;  b,  elevator  to  feed  c;  c,  disintegrator;  d,  elevator  to  storage  tower;  e,  coal- 
*,  air  inlet  to  ovens;  /,  charging  holes  for  coal;  k,  gas  flue;  /,  chimney  to  be  used  if  gases  are  n 
ram  (pushing  machine)  travels  parallel  with  ovens;  o,  coke  discharge  side;  q,  tracks  for  chargii 


[)VENS  WITH  CRUSHER.     BERNARD'S  SYSTEM 


t  tower;  f,  engine;  g,  boiler  heated  by  waste  gases;  h,  twenty  retort  coke  ovens  without  saving  of  by-products; 
:1  for  boiler  heating;  m,  chimney  to  be  used  if  gases  are  used  for  boiler  heating;  n,  machine  side  of  ovens  where 
•ies;  r,  tracks  for  windlass  for  raising  doors  of  ovens;  s,  water  supply. 


TREATISE  ON  COKE  379 

The  plan  of  the  coke  ovens  is  of  the  most  modern  design. 
Figs.  7  and  8,  Chapter  V,  show  the  plan,  section,  and  all  details. 
In  the  front  of  this  oven  a  double  brick  arch  is  seen  above  the 
shaped  firebrick  arch  over  the  oven  door.  These  ovens  have  been 
constructed  of  the  best  materials  and  in  the  most  substantial 
manner,  under  the  general  superintendence  of  Mr.  Harry  McCreary, 
of  Indiana,  Pennsylvania. 

The  coke  wharves  to  these  ovens  are  very  wide,  so  as  to  store 
coke  during  periods  of  a  deficient  supply  of  railroad  cars.  They 
are  faced  with  permanent  masonry  retaining  walls  of  increased 
height  to  meet  the  needs  of  modern  steel  coke  cars. 

The  miners'  hamlet  is  a  model  of  neatness  and  excellent  sani- 
tary conditions.  The  whole  plant  is  operated  by  steam  and 
electric  power,  with  the  intelligent  application  of  modern  labor- 
saving  machinery.  A  general  view  of  the  plant  is  shown  in  Fig.  15. 
This  plant  has  been  laid  out  under  the  general  superintendence 
of  Mr.  Harry  McCreary,  ably  assisted  by  Mr.  R.  M.  Mullen,  civil 
engineer. 

Mr.  Joseph  Wharton,  LL.  D.,  of  Philadelphia,  has  not  been 
sparing  of  means  in  the  construction  of  this  excellent  coking  plant. 
It  is  most  complete  in  all  its  parts,  and  should,  under  intelligent 
management,  afford  satisfactory  results  in  both  the  quantity  and 
quality  of  its  product. 

Mr.  Wharton  owns  and  operates  a  number  of  large  blast  fur- 
naces at  Wharton,  New  Jersey.  The  coke  from  this  and  another 
coke  plant  in  the  Connellsville  region  goes  to  these  blast  furnaces. 


RETORT-OVEN  PLANTS 

The  plan  and  elevation,  Fig.  16,  show  the  general  requirements 
in  locating  retort  coke  ovens.  It  will  be  seen  that  the  require- 
ments in  their  location  differ  materially  from  the  location  of  the 
beehive  ovens,  in  the '  wider  spaces  demanded  for  the  steam 
ram  or  pushing  engine  for  discharging  the  coke  from  the  retort 
ovens.  In  the  above  instance,  a  width  of  45  feet  is  required  for 
steam  connections  and  pushing  engine.  In  the  beehive  ovens,  the 
coke  is  usually  drawn  out  by  manual  labor,  requiring  only  30  feet 
of  wharf  room,  while  in  the  retort  ovens  40  feet  width  in  wharves 
is  required  on  both  sides  of  the  ovens. 

The  plan  shows  the  method  of  locating  a  bank  of  20  Bernard 
coke  ovens,  with  coal  dump  or  hopper  for  receiving  the  coking  coal 
from  the  mine  or  railroad  cars,  with  elevators,  disintegrator,  and 
storage  tower;  all  in  close  relations  to  the  bank  of  coke  ovens.  The 
coal-storage  tower  has  double  hoppers  below,  through  which  the 
coal  is  loaded  into  the  charging  larry. 

The  steam  boilers  are  placed  at  the  end  of  the  bank  of 
ovens,  and  are  usually  fired  by  the  gases  from  the  coke  ovens; 


380  TREATISE  ON  COKE 

but  in  case  of  failure  of  an  adequate  supply  of  gas,  the  defi- 
ciency can  readily  be  obtained  in  coal  from  the  adjoining  coal- 
storage  tower. 

The  space  on  the  wharf  required  for  discharged  coke  is,  in 
this  instance,  40  feet  wide  to  receive  the  charge  of  coke  from  the 
ovens,  which  are  30  feet  long. 

The  bank  of  ovens  can  be  extended  to  embrace  a  line  of  GO 
coke  ovens.  When  a  greater  number  is  required,  parallel  banks  can 
be  readily  located.  If  the  by-products  are  to  be  saved,  the  neces- 
sary exhausting  and  condensing  apparatus  can  be  placed  imme- 
diately behind  the  coal-storage  tower,  in  a  building  set  apart  for 
these  uses. 

In  locating  large  plants  of  retort  coke  ovens  in  parallel  banks, 
the  exhausting  and  condensing  appliances  can  be  proportioned 
to  supply  two  banks  of  60  ovens  each.  A  similar  application  can 
be  made  of  the  apparatus  for  treatment  of  coal,  when  it  may  be 
found  necessary,  that  is,  one  apparatus  to  supply  two  banks  of 
coke  ovens. 

In  most  cases  it  is  considered  prudent  to  establish  duplicate 
condensing  apparatuses,  as  any  interruption  to  this  part  of  the  work 
would  produce  general  disorder. 

Steam  rams  or  pushing  engines  have  been  constructed  under 
different  plans.  Some  of  these  engines  carry  with  them  a  steam 
boiler,  while  others  receive  their  steam  through  ingenious  arrange- 
ments of  movable  steam  pipes  from  stationary  boilers. 

The  gradients  of  railroad  sidings  and  charging  larry  tracks 
should  be  governed  by  the  same  principles  that  are  found  neces- 
sary to  economy  of  work  in  beehive  ovens.  In  some  cases  the 
retort  ovens  are  located  in  the  immediate  neighborhood  of  the 
blast  furnaces,  and  the  coke  is  handled  from  the  former  to  the  lat- 
ter in  the  usual  coke  barrows.  Even  in  this  location,  gradients 
descending  with  the  tonnage  will  conduce  to  facility  and  economy 
of  this  work. 

In  the  foregoing  considerations  of  the  location  of  plants  of 
coke  ovens,  the  sites  have  been  contemplated  at  or  quite  near  the 
coal  mines.  The  usual  quantity  of  coal  to  make  1  ton  of  coke  is 
1.5  to  1.7  tons.  The  economy  of  locating  coke  works  at  the  coal 
mines  is  based  on  the  less  freight  charge  on  1  ton  of  coke,  against 
the  charge  on  1.4  or  1.6  tons  of  coal. 

It  is  quite  evident  that  in  most  cases  this  method  of  locating 
the  coke  ovens  at  the  coal  mines  is  the  true  policy.  It  has,  how- 
ever, some  drawbacks.  There  is  usually  a  loss  of  2  or  3  per  cent, 
in  the  loading  of  coke  at  the  ovens  and  unloading  it  at  the  furnaces 
or  steel  works.  In  the  wet  and  winter  seasons  it  occasionally 
receives  2  to  3  per  cent,  of  moisture  in  the  transit.  But  the  loss 
in  both  of  these  would  not  compensate  for  the  increased  freight 
on  coal  to  make  coke  at  the  furnaces  or  steel  works,  provided  that 
the  freight  charges  per  ton  are  equal. 


TREATISE  ON  COKE  381 

PRODUCTION  OF  ILLUMINATING  GAS  FROM  COKE  OVENS* 

The  object  of  this  paper  is  to  describe  the  progress  that  has 
been  made  in  the  United  States  and  Canada  in  recovering  illumi- 
nating gas  from  by-product  coke  ovens.  A  clear  account  of  this 
cannot  be  given  without  repeating  some  of  the  previous  state- 
ments published.! 

Before  entering  upon  the  subject,  I  cannot  resist  the  tempta- 
tion of  discussing  its  bearing  upon  the  vexed  smoke  problem  of 
large  cities. 

% 

The  Fuel  Supply  of  Large  Cities. — The  question  of  the  fuel  sup- 
ply of  large  cities  is  of  the  greatest  importance.  Nothwithstanding 
this  fact,  its  study  has  been  neglected  in  a  distressing  manner. 
We  still  see  the  large  manufacturing  cities  in  Great  Britain,  as  well 
as  in  the  United  States  and  other  countries,  darkened  and  begrimed 
with  clouds  of  smoke  and  soot  resulting  from  the  use  of  bituminous 
coal.  The  annual  expenditure  for  the  maintenance  of  buildings, 
etc.  is  increased,  not  to  mention  the  deleterious  effect  on  the 
health  of  the  people. 

The  subject  has  been  discussed  by  George  Beilby  in  his  presi- 
dential address  before  the  Society  of  Chemical  Industry. J  He 
gives  the  following  table: 


CONSUMPTION  OF  COAL  IN  THE  UNITED  KINGDOM  IN  1898 

Coal  for  the  generation  of  power  in  industries:  LONG  TONS 

Railways 10,000,000  to  12,000,000 

Coasting  steamers 6,000,000  to    8,000,000 

Mines. 10,000,000  to  11,000,000 

Factories 38,000,000  to  40,000,000 


Total 71,000,000 


*Paper  read  before  the  gas  section  of  the  Engineering  Congress  at  Glas- 
gow by  F.  Schniewind,  Ph.  D, 

t  (a)  Professor  Hoffmann's  extract  from  Dr.  F.  Schnie wind's  test 
report  on  Dominion  coal  at  Glassport,  Pennsylvania,  "The  Production  of 
Illuminating  Gas  in  By-Product  Coke  Ovens  "  Engineering  and  Mining 
Journal,  October  8  and  15,  1898;  Progressive  Age,  1898,  page  575.  (6)  "The 
Everett  Coke-Oven  Gas  Plant,"  Progressive  Age,  August  15,  and  September  1, 
1899;  January  1,  1900;  Journal  of  Gas  Lighting,  Vol.  LXXIV  pages  1,114, 
1,176;  Vol.  LXXV,  page  274;  Vol.  LXXVII,  pages  616,  679,  749,  *82o! 
(c)  "Otto-Hoffman  Coke-Oven  Practice."  American  Gas  Light  Journal, 
Vol.  LXXVII,  page  444.  (d)  "By-Product  Coke  in  the  United  States" 
Iron  Age,  Vol.  LXXVIII,  page  14. 

JJournal  of  the  Society  of  Chemical  Industry,  Vol.  XVIII,  page  643; 
Journal  of  Gas  Lighting,  Vol.  LXXIV,  page  175. 


382  TREATISE  ON  COKE 

Coal  for  the  generation  of  heat  in  industries:  LONG  TONS 

Blast  furnaces 16,000,000  to  18,000,000 

Steel  and  malleable-iron  works. .  10,000,000  to  12,000,000 

Other  metallurgical  works 1,000,000  to    2,000,000 

Chemical   works,    potteries,    and 

glass  works 4,000,000  to    0,000,000 

Gasworks 13,000,000 


Total 51,000,000 

Coal  for  domestic  purposes 35,000,000 

Coal  for  the  generation  of  power  in  industries,  as  tabulated 

on  page  381 71,000,000 

Total  consumption ,,-..; YW->. -.  ...       157,000,000 

Of  this  amount  of  bituminous  coal,  only  a  very  small  percent- 
age is  subjected  to  dry  distillation,  which  converts  it  into  smoke- 
less coke  (see  following  table) ;  the  remainder  is  almost  entirely 
burned  directly,  under  conditions  that  are  favorable  to  the  pro- 
duction of  smoke. 

COAL  SUBJECTED  TO  DRY  DISTILLATION  IN  THE  UNITED 
KINGDOM  IN  1898 

LONG  TONS 

Gasworks 13,000,000 

Blast  furnaces 2,000,000 

By-product  coke  ovens 1,250,000 

Total 16,250,000 

This  figure  does  not  include  the  coal  coked  in  beehive  ovens 
without  the  recovery  of  by-products,  which  amount  is  approxi- 
mately 12,500,000  long  tons.  , 

Mr.  Beilby  suggests  two  solutions  of  the  smoke  problem: 
(1)  the  use  of  improved  appliances  for  the  combustion  of  the  raw 
coal,  and  (2)  the  transformation  of  the  raw  coal  into  smokeless 
fuel  by  carbonization  or  gasification. 

We  are  of  the  opinion  that  the  first  method  offers  only  a  partial 
relief,  and,  furthermore,  that  it  is  a  wasteful  one,  because  valuable 
products  can  be  recovered  from  bituminous  coal  by  dry  distilla- 
tion that  are  wasted  in  the  direct  combustion  of  raw  coal.  The 
second  method,  i.  e.,  that  of  the  conversion  of  the  raw  coal  into  a 
smokeless  fuel  by  carbonization,  seems  to  us  the  most  rational 
and  economical  solution  of  the  problem.  This  method  has,  in  the 
meantime,  developed  to  a  very  considerable  extent  in  the  United 
States.  The  United  Coke  and  Gas  Company,  of  New  York,  has 
introduced  into  the  United  States  by-product  coke-oven  systems 
exploited  by  Dr.  C.  Otto  &  Co.,  of  Germany,  chiefly  the  Otto- 
Hoffman  coke  ovens.  A  large  number  of  these  plants  have  been 
erected.  In  Germany,  these  plants  are  operated  almost  entirely 
for  the  production  of  metallurgical  coke,  while  the  surplus  gas  is 
burned  under  boilers.  A  number  of  the  American  plants  operate 


TREATISE  ON  COKE 


383 


in  the  same  way,  but  several  of  the  later  plants  are  designed 
for  the  exclusive  manufacture  of  domestic  and  railroad  coke  and 
illuminating  gas. 

A  very  large  proportion  of  the  coal,  as  given  in  Mr.  Beilby's 
table,  is  consumed  in  or  near  large  cities,  and  we  believe  this  coal 
should  be  subjected  to  a  carbonizing  process  before  use.  This 
would  supply  to  the  city  at  once  a  cheap  smokeless  fuel  suitable 
for  practically  all  purposes.  We  will  show  further  on  that  the  use 
of  coke  instead  of  coal  would  not  be  coupled  with  a  great  expense 
to  the  fuel  consumer.  By  the  erection  of  large  carbonizing  works 
near  or  in  large  cities,  the  smoke  problem  would  find  its  ready 
solution;  and  at  the  same  time,  a  great  saving,  from  a  national 
economic  point  of  view,  would  result  from  the  recovery  of  the 
valuable  by-products  and  gas. 

How  urgent  the  demand  for  smokeless  fuels  has  become  is 
plainly  shown  by  the  fuel  statistics  of  some  of  the  larger  American 
cities.  In  the  United  States,  anthracite  is  found  in  a  small  dis- 
trict in  Pennsylvania,  while  bituminous  coal  is  scattered  over 
almost  all  the  states  east  of  the  Mississippi.  Notwithstanding  the 
close  proximity  of  the  bituminous  coal  fields  to  some  of  the  larger 
cities,  enormous  quantities  of  anthracite  are  brought  to  them  from 
a  great  distance,  and  consequently  at  great  expense. 

The  following  table  demonstrates  how  enormous  the  demand 
for  smokeless  fuel  has  become,  and  furthermore,  that  a  great 
premium  is  paid  for  the  smokeless  character  of  the  fuel.  The 
prospects  are,  therefore,  encouraging  for  the  erection  of  carbonizing 
plants  near  large  cities. 

FUEL  STATISTICS  OF  SOME  AMERICAN  CITIES  FOR  1900 


Bituminous  Coal 

Anthracite 

Quantity 

Used 
Net  Tons 

Price  Per 
Net  Ton 
Dollars 

Quantity 
Used 
Net  Tons 

Price  Per 
Net  Ton 
Dollars 

New  York  

1,700,000 
2,050,000 
7,000,000 

2.  50  to  3.50 
2.00  to  3.00 
2.50  to  3.50 
2.00  to  3.00 

3,300,000 
1,950,000 
1,600,000 

3.50  to  4.00 
4.00  to  4.50 
4.00  to  5.00 
5.00  to  6.00 

Philadelphia  

Boston  

Chicago  

NOTE. — The  total  amount  of  bituminous  coal  and  anthracite  for  domes- 
tic consumption  and  the  supply  of  steamers  in  New  York  and  adjacent  cities 
belonging  to  the  port  of  New  York  is  estimated  at  15,000,000  net  tons. 

In  order  to  facilitate  an  understanding  of  the  more  detailed 
account  of  the  process,  a  general  description  of  the  combined  coke- 
oven  and  gas  process  is  first  given,  comparing  it  at  the  same  time 
with  ordinary  gas-retort  practice. 


384  TREATISE  ON  COKE 

The  coke  ovens  have  a  charging  capacity  of  16,000  pounds  of 
coal,  which  is  all  carbonized  in  24  hours  and  less.  Ordinary  gas 
retorts  have  a  charging  capacity  of  only  300  to  400  pounds,  which 
is  carbonized  in  about  4  hours. 

On  account  of  the  increased  charge,  all  the  operations  around 
the  coke  ovens  are  performed  by  machinery,  which  results  in  a 
saving  of  labor  per  ton  carbonized,  as  compared  with  the  present 
coal-gas  system. 

On  account  of  the  larger  charges  and  the  peculiar  construction 
of  the  coke  ovens,  a  far  better  coke  is  produced,  as  compared  with 
that  obtained  in  ordinary  small  gas  retorts.  The  coke  oven  yields, 
if  required,  a  coke  that  satisfactorily  sustains  the  burden  of  a 
modern  large-sized  blast  furnace.  It  is  consequently  of  much 
higher  value  than  gasworks  coke.  The  coke  oven  may  also  produce 
domestic  coke  far  superior  to  gasworks  coke. 

The  coke  oven,  like  the  ordinary  gas  retort,  saves  tar  and 
ammonia,  and  eventually  several  additional  by-products.  The 
coke  oven  yields,  however,  a  higher  percentage  and  a  better  quality 
of  these  products  than  the  gas  retort. 

The  ordinary  gas  retort  produces  the  heat  necessary  for  car- 
bonizing the  coal  by  burning  a  part  of  the  resulting  coke  under 
the  benches.  In  the  coke-oven  process,  all  the  coke  is  saved, 
while  a  part  of  the  resulting  gas  is  burned  under  the  ovens. 


.  THE  EVERETT  COKE-OVEN  GAS  PLANT* 

The  property  consists  of  about  288  acres  of  land  in  Everett  and 
Chelsea,  Massachusetts.  This  is  largely  tidal  marsh  land,  but  a 
ridge  of  gravel  extends  from  Beacham  Street,  Fig.  17,  to  the  point 
between  Mystic  and  Island  End  rivers.  This  gave  excellent 
material  for  filling  and  also  for  making  concrete.  The  character 
of  the  ground  necessitated  a  great  deal  of  piling.  There  was 
driven  a  total  of  about  35,000  piles,  and  immediately  upon  these 
piles  a  cap  of  concrete  was  put. 

The  present  plant  of  400  ovens  occupies  but  a  small  part  of 
the  property.  The  design  of  the  plant  permits  of  an  increase  to 
1,200  ovens,  the  erection  of  which  number  is  ultimately  contem- 
plated. The  next  set  of  400  ovens  will  be  located  between  the 
present  plant  and  the  wharf,  and  the  third  between  the  present 
plant  and  the  purifying  house. 

Coal-Handling  Plant. — The  coal  employed  is  washed  Cape 
Breton  slack  coal  received  from  the  Dominion  Coal  Company. 
The  coal-handling  plant  was  designed  by  L.  J.  Hirt,  the  chief 
engineer  of  the  New  England  Gas  and  Coke  Company,  and  is  on 
the  rope-haulage  principle. 

*By  Dr.  F.  Schniewind,  in  Progressive  Age  for  August  15,  1899. 


TREATISE  ON  COKE 


385 


The  steamers  land  the  coal  on  the  company's  wharf,  Fig.  17. 
On  top  of  the  6,000-ton  coal  bin  A,  three  hoisting  towers  are 
provided  with  so-called  "clam-shell"  grab  buckets  of  1.5  tons 
capacity.  The  speed  of  unloading  is  about  150  to  200  tons  per 


FIG.  17.     PLAN  OF  WORKS,  NEW  ENGLAND  GAS  AND  COKE  COMPANY 

tower  per  hour  from  the  full  cargo.     During  the  "trimming"  of 
the  coal  the  capacity  is  of  course  reduced. 

Underneath  the  bin  are  three  tracks  provided  for  coal  larries, 
or  cars  holding  about  2.5  tons  each.  There  are  thirty  of  these 
larries.  The  loaded  larries  run  by  gravity  to  the  north  end  of 
bin  A,  where  they  are  connected  with  the  cable,  which  carries 


386 


TREATISE  ON  COKE  387 

them  to  the  four  coal  bins  3,  4,  ®>  1  (of  &  capacity  of  2,000  tons 
each)  at  the  ovens,  and  into  the  large  storage  yard  F.  The  latter 
provides  for  the  storage  of  80,000  tons  of  coal  and  consists  of  a 
wooden  trestle  from  which  the  coal  can  be  dumped  upon  the  ground. 
From  this  pile,  a  movable  double  tower  can  pick  up  the  coal  on 
either  side  of  the  trestle  and  transfer  it  back  to  the  coal  larries, 
which  then  convey  it  to  the  oven  bins. 

It  is  during  a  short  period  in  March  or  April  only  that  the 
Cape  Breton  harbors  (Louisburg  and  Sidney),  from  which  the  coal 
is  shipped,  are  icebound,  and  consequently  with  the  beginning  of 
winter  sufficient  coal  will  be  accumulated  to  tide  the  works  over 
this  period. 

At  present,  the  motive  power  for  the  coal  towers  on  top  of  the 
storage  bin  ^4,  as  also  for  the  cable-driving  machinery,  is  steam, 
but  it  is  the  intention  to  operate  these  by  electricity.  All  the  bins 
are  of  steel  with  wooden  lining. 

The  coke  ovens  are  arranged  in  eight  groups,  or  batteries,  of 
50  each,  B1-B8,  Fig.  17.  Two  of  these  groups,  100  ovens,  form 
one  working  unit  and  are  supplied  with  coal  from  one  bin.  Bat- 
teries B1,B2,  B3,  B4  are  connected  with  stack  M,  and  B5,  B6,  B7,  B8 
with  stack  N.  The  batteries  are  erected  on  high  foundations  for 
two  reasons,  viz. :  first,  to  bring  the  bottom  of  all  flues  above 
extreme  high  water,  and  second,  to  admit  of  dumping  the  coke 
into  the  highest  railroad  cars  without  another  lifting. 

At  present,  batteries  Bl  and  B3  are  in  operation,  and  battery 
B2  is  being  heated  by  means  of  some  surplus  gas  from  batteries 
Bl  and  B3. 

Capacity. — The  retorts  are  33  feet  long,  nearly  6  feet  high,  and 
18  inches  average  width,  and  have  a  capacity  of  6  net  tons  coal 
per  charge.  They  are  of  the  Otto-Hoffman  type  with  several 
modifications  to  adapt  them  to  the  present  requirements. 

Firebrick. — Unusual  care  has  been  taken  in  truing  the  brick 
used  for  erecting  the  walls,  and  so  successful  have  been  these 
efforts  that  no  allowance  had  to  be  made  for  joints.  The  impor- 
tance of  obtaining  gas-tight  walls  is  manifest.  As  in  these  works 
the  gas  is  of  more  importance  than  usual  with  coke  ovens;  this 
care  was  wise. 

It  has  been  found  that  the  average  American  firebrick  is  far 
more  refractory  than  the  European -coke-oven  brick,  but  never- 
theless even  the  best  brands  are  generally  not  suitable  for  retort 
coke  ovens.  The  reason  is  the  considerable  shrinkage  of  these 
American  brick  when  exposed  to  high  heat. 

The  strains  on  coke-oven  brick  are  very  severe,  as  the  walls 
in  the  bottom  flues  are  subjected  to  very  high,  continuous  tem- 
peratures from  all  sides,  while  again  in  another  part  (the  retort 
proper)  the  brick  are  subject  to  sudden  cooling  by  the  cold  and 
sometimes  wet  coal  charges  and  to  the  mechanical  abrasion  of 
the  coke  charge  when  pushed  out. 


TREATISE  ON  COKE  389 

The  first  Otto-Hoffman  plants,  when  built  in  this  country,  viz., 
at  Cambria  Steel  Company,  Johnstown,  and  the  Pittsburg  Gas 
and  Coke  Company,  Glassport,  Pennsylvania,  experienced  consider- 
able trouble  on  this  account.  But  the  problem  had  to  be  solved, 
as  the  introduction  of  the  retort  oven  into  the  United  States 
depended  on  the  securing  of  suitable  domestic  firebrick;  and  it 
may  be  said  that  by  properly  using  various  refractory  materials 
the  problem  has  been  solved  so  successfully  that  GO  ovens  at 
Johnstown,  now  in  continuous  operation  for  2  years,  do  not  show 
the  slightest  cracks  or  deviations  from  their  original  dimensions. 

Charging. — The  coal  charge  is  brought  from  the  bin  to  the 
ovens  by  means  of  an  electric  charging  machine  (not  shown  in  the 
illustrations)  and  filled  into  the  retort  through  three  charging 
holes  in  the  roof,  a,  a1?  a2,  Fig.  19.  The  coal  is  then  leveled  by 
introducing  scrapers  through  small  holes  b  and  bf  in  the  two 
doors,  c  and  c' .  When  this  charge  is  level,  holes  b  and  bf  are 
closed  and  luted,  and  the  same  is  done  with  the  three  charging 
holes,  a,  a1?  a2- 

Removal  of  Gases. — The  evolution  of  gases  and  vapors  has  at 
once  commenced  with  the  charging  of  the  coal.  By  raising  the 
drop  valve  d,  the  products  of  distillation  are  permitted  to  escape 
through  standpipe  e  into  the  gas-collecting  main  /.  It  should  be 
mentioned  that  this  is  a  dry  main  and  not  a  hydraulic  main. 
The  mains  are  kept  free  of  pitch  by  a  tar  flushing  system. 

The  Coking  Time. — The  charge  of  coal,  6  net  tons,  is  carbon- 
ized in  from  24  to  30  hours.  This  time  varies  from  several  causes, 
among  which  is  an  important  one — the  character  of  the  coke  that 
it  is  intended  to  produce.  If  we  wait  until  the  last  traces  of  vola- 
tile matter  are  expelled,  then  we  will  produce  a  very  hard  coke, 
but  will  require  a  long  coking  time.  If,  on  the  other  hand,  we 
push  the  oven  before  the  last  traces  of  volatile  matter  are  driven 
off,  then  the  coke  is  softer  and  better  suited  for  domestic  and 
boiler-firing  purposes  and  the  coking  time  is  materially  reduced. 

In  the  beginning,  60  ovens  were  pushed  per  day  out  of  the  100 
in  operation.  With  the  growing  demand  for  coke,  this  number 
was  increased  to  80  ovens.  This  corresponds  to  a  coking  time  of 
30  hours.  But  with  this  modus  operandi  a  considerable  number, 
from  20  to  30  ovens,  are  always  "around,"  i.  e.,  ready  to  be  pushed. 
Thus,  the  coking  could  easily  be  reduced  to  24  hours,  and  will  be 
shortly  with  the  constantly  increasing  orders  for  coke. 

Discharging  of  the  Coke. — When  the  oven  has  ceased  to  give 
off  gas, -which  can  be  ascertained  through  small  holes  in  the  doors, 
the  valve  df ',  Fig.  19,  is  closed  and  thus  the  oven  is  disconnected 
from  the  poor  gas  main  /'.  The  charging-hole  covers  a,  alt  a2 
are  then  opened  and  the  oven  is  ready  for  the  coke  pusher. 

In  order  to  distribute  the  fresh  charges  over  the  entire  battery, 
a  regular  rotation  of  pushing  the  ovens  has  been  established. 
Beginning,  for  instance,  with  oven  No.  1  at  one  end  of  the  battery, 


390  TREATISE  ON  COKE 

the  next  ovens  are  11,  21,  31,  and  41;  after  this,  ovens  Nos.  6,  16, 
26,  36,  and  46  are  pushed.  This  is  followed  throughout  the  entire 
100  ovens.  It  is  apparent  that  such  an  arrangement  makes  it 
impossible  to  charge  two  adjoining  ovens  in  short  succession. 

The  electric  coke  pusher  /,  Fig.  19,  is  then  brought  opposite 
the  oven  ready  to  be  pushed.  The  doors  at  both  ends,  c  and  cf, 
are  hoisted  by  means  of  electric  contrivances,  situated  at  the  end 
of  each  battery.  Rollers  u  are  provided  over  each  door,  on 
which  a  long  bar  is  resting,  which  connects  with  the  electric  door 
hoist.  Whenever  a  chain  is  attached  to  the  door  and  to  this  bar 
and  the  bar  moved  sidewise,  the  door  will  be  raised. 

The  electric  coke  pusher  /  consists  of  a  long  rack  and  pinion 
that  forces  through  the  oven  a  shield  k  bearing  against  the  coke 
charge.  Thus,  the  entire  charge  of  coke  is  forced  out  toward  the 
coke  side.  In  order  to  facilitate  the  moving  of  the  charge,  the 
oven  is  a  little  wider  at  the  discharge  end  than  at  the  pusher  side. 
The  hot  coke  then  falls  into  the  electric  coke-loading  machine  y. 
A  jet  of  water  is  thrown  upon  the  coke  immediately  upon  its 
leaving  the  oven. 

The  coke  loader  consists  of  a  long,  inclined  pan  w  capable  of 
holding  the  entire  charge  of  about  4.5  net  tons  of  coke.  In  order  to 
obtain  a  good  distribution  of  the  coke  in  this  pan,  the  entire  machine 
is  moved  sidewise  while  the  coke  is  coming  out.  As  soon  as  the 
charge  is  on  the  pan,  this  travels  with  its  hot  charge  to  one  side, 
and  a  second  loading  machine  finishes  the  operations  at  the  oven. 
Thus,  the  men  are  not  exposed  to  the  high  heat  from  the  glowing 
coke.  The  hot  charge  then  receives  another  quenching.  When 
the  coke  is  fully  cooled,  partly  by  water  and  partly  by  the  air, 
the  pan  is  tilted  and  the  gates  x  are  opened,  which  allows  the 
entire  coke  charge  to  slide  into  the  railroad  cars  g. 

Immediately  after  the  coke  has  been  pushed  out,  the  pusher 
bar  is  withdrawn  and  the  doors  c  and  c'  are  lowered.  The  doors 
are  forced  close  against  the  brickwork  of  the  oven  by  means  of 
bars,  held  in  buckstaves  v  between  the  ovens,  and  wedges.  After 
this  the  doors  are  sealed  hermetically  by  throwing  loam  around 
the  same,  and  the  oven  is  ready  for  another  charge.  The  entire 
operation  of  discharging  the  oven  and  recharging  the  same  is  com- 
pleted in  about  10  to  12  minutes. 

Disposal  of  the  Coke. — All  the  coke  coming  from  the  ovens  is 
first  loaded  into  railroad  cars.  The  New  England  Gas  and  Coke 
Company  owns  150  cars,  which  are  of  improved  open  top-rack 
type.  The  capacity  of  these  cars  is  about  22  to  25  tons.  Provi- 
sions are  also  made  to  load  the  coke  into  box  cars.  The  coke 
coming  from  the  ovens  consists  chiefly  of  columnar  pieces  about 
9  inches  long.  With  these  pieces  is  mixed  a  small  percentage  of 
smaller  pieces.  This  coke  is  called  "run-of-oven  coke,"  and  is 
shipped  directly  for  use  under  boilers,  locomotives,  for  metallur- 
gical purposes,  etc. 


TREATISE  ON  COKE  391 

If  the  coke  is  to  be  used  for  domestic  purposes,  the  railroad  cars 
are  switched  to  a  coke  crusher  by  which  it  is  broken  into  different 
sizes  and  screened.  The  different  sizes  are  collected  in  separate 
bins,  from  which  they  are  drawn  into  railroad  cars  for  shipment. 
The  railroad  cars  can  be  shifted  directly  on  to  lighters  that  trans- 
fer the  coke  to  any  of  the  large  coal  yards,  etc.  in  Boston.  Pro- 
visions are  also  being  made  to  load  the  coke  in  bulk  into  steamers 
and  sailboats.  There  is,  furthermore,  in  construction  a  large 
storage  yard  capable  of  holding  about  50,000  tons  of  coke  for  the 
winter  trade,  and  a  movable  crane  is  being  erected,  which  has  a 
span  of  200  feet  and  travels  a  distance  of  600  feet,  thus  covering 
a  total  area  of  120,000  square  feet.  This  crane  will  either  load 
the  coke  from  the  cars  on  to  the  storage  pile,  without  breaking  it 
by  a  high  drop,  or  will  load  it  back  from  the  pile  into  the  cars. 


CHAPTER  X 


GENERAL  CONCLUSIONS  ON  THE  WORK,  COST,  AND  PROD- 
UCTS OF  THE  SEVERAL  TYPES  OF  COKE  OVENS 

Adaptability  of  Different  Ovens  in  the  Several  Coal  Fields. — In 

the  eastern  and  middle  coal  fields  of  the  United  States,  the  areas 
of  the  sections  of  the  coal  measures  whose  beds  are  adapted  for 
the  manufacture  of  coke,  in  greater  and  less  degrees,  have  been 
generally  well  defined.  Much  has  yet  to  be  done  in  the  great 
far  West  in  the  further  development  of  its  coal  fields,  and 
in  determining  the  special  localities  affording  coal  suitable  for 
making  coke. 

So  far  as  our  present  knowledge  extends,  there  are  at  present 
four  well-known  groups  or  sections  of  coking  coals.  These  areas 
of  coking  coals  are  found  in  meridional  strips,  conforming  in  their 
general  southwestward  courses  to  the  crest-line  trends  of  the 
Appalachian  mountain  chains.  They  are  found  in  the  following 
order  from  west  to  east: 

Section  1.  The  several  types  of  coals  very  rich  in  bituminous 
matter,  affording  a  light  coke  with  a  highly  inflated  physical 
structure,  and  not  regarded  as  a  desirable  fuel  for  metallurgical 
purposes.  This  class  of  coals  contains  from  35  to  40  per  cent,  of 
volatile  matter. 

Some  efforts  have  been  made  to  coke  these  coals;  evidently  the 
progress  thus  far  has  not  been  quite  satisfactory.  Treatment  in 
the  horizontal  types  of  ovens  appears  to  have  produced  the  best 
results;  but  the  coke  is  usually  spongy,  inheriting  an  inflated  phys- 
ical structure  and  lacking  the  hardness  of  body  so  essential  to  a 
good  metallurgical  fuel.  It  is  coming  to  be  understood  that  this 
class  of  rich  bituminous  coals  requires  a  moderate  oven  heat  to 
secure  the  best  possible  coke. 

A  serious  difficulty  has  embarrassed  the  efforts  hitherto  made 
to  produce  clean  metallurgical  coke  from  these  coals,  from  the 
rather  large  percentage  of  sulphur  inherited  by  most  of  them. 
This  sulphur  is  found  generally  interleaved  in  the  bedding  planes 
of  the  coal,  as  well  as  scattered  through  it  in  thin  scales.  The 
attenuated  condition  of  this  sulphur  admixture  constitutes  the 
chief  difficulty  in  efforts  to  reduce  or  remove  it  by  the  ordinary 
processes  of  disintegration  and  washing.  A  practical  plan  for 

392 


TREATISE  ON  COKE  393 

reducing  this  thinly  mingled  sulphur  from  these  western  coals 
would  enable  a  coke  to  be  made  from  them  that  could  be  used 
in  whole  or  in  part  of  blast-furnace  operations. 

A  broad  horizontal  oven,  with  flues  under  its  floor,  heated  with 
returned  gas  evolved  in  coking,  and  without  side  flues,  would 
probably  be  the  best  method  of  reducing  the  injurious  action  of 
the  surplus  fusing  matter  in  these  coals.  This  would  be  a  some- 
what different  application  of  the  meiler  or  mound  principle  of 
coking  coal.  It  is  probable  that  a  mixture  of  the  class  of  dry 
coking  coals  with  these  rich  bituminous  coals  would  produce  a 
firm  coke.  This,  however,  would  involve  the  additional  expense 
of  freight,  with  extra  care  and  labor  in  mixing  the  coals. 

It  is  important  to  note  that  the  area  of  this  section  of  rich 
bituminous  coal  is  by  far  the  largest,  in  fact  larger  than  all  the 
others  together.  It  follows,  therefore,  that  it  presents  an  inviting 
field  for  further  experiment  in  determining  the  best  type  of  coke 
oven  for  the  successful  production  of  useful  coke  in  this  large  area 
of  bituminous  coal. 

The  type  of  coke  oven  to  produce  the  best  possible  coke,  with 
the  saving  of  by-products,  would  evidently  follow  promptly  the 
success  of  cleaning  the  coal  for  the  manufacture  of  coke. 

Section  2.  This  small  section  embraces  the  best  qualities  of 
coals  for  the  manufacture  of  coke.  They  contain  25  to  35  per 
cent,  of  volatile  matter.  The  strip  is  narrow,  averaging  3  to  5 
miles  wide  in  Southwestern  Pennsylvania,  located  parallel  to  and 
west  of  the  Chestnut  Ridge.  It  constitutes  the  celebrated  Connells- 
ville  coke  region.  It  extends  through  West  Virginia,  inheriting 
in  that  state  a  slightly  increased  volume  of  bituminous  matter. 
The  cokes  made  from  these  coals  are  firmly  established  as  regards 
purity  and  calorific  energy  in  all  metallurgical  operations. 

Section  3.  This  section,  consisting  6f  the  dryer  qualities  of 
coking  coals,  is  next  in  magnitude  to  Section  1  and  only  secondary 
in  quality  to  Section  2.  These  coals,  under  careful  oven  treat- 
ment, afford  good  coke;  they  contain  20  to  25  per  cent,  of  volatile 
combustible  matter. 

This  strip  is  located  in  Pennsylvania,  Maryland,  and  the  Vir- 
ginias. It  is  situated  along  the  eastern  border  of  the  Appalachian 
field.  Its*  coal  can  be  coked  in  horizontal  ovens  with  fairly  good 
results;  but,  with  some  exceptions,  it  does  not  usually  inherit  the 
hardness  of  body  and  calorific  energy  of  the  cokes  from  the  coals 
of  Section  2. 

It  is  quite  evident  that  the  vertical  types  of  coke  ovens  are 
best  adapted  for  the  production  of  the  best  quality  of  coke  from 
this  family  of  coals,  as  they  confer  on  it  the  essential  physical 
property,  hardness  of  body,  which  assures  its  value  as  a  blast- 
furnace fuel.  They  would  also  afford  an  increased  percentage  of 
coke  from  these  rather  dry  coals  as  compared  with  the  horizontal 
type  of  coke  ovens. 


394  TREATISE  ON  COKE 

It  is  also  evident  that  in  using  the  vertical  or  retort  coke  oven, 
in  making  coke  from  these  coals,  the  plant  should  be  provided 
with  the  necessary  apparatus  for  saving  the  by-products  of  tar  and 
ammonia  sulphate,  as  the  profits  from  these  will  be  found  helpful 
on  the  credit  side  of  earnings. 

As  it  is  now  becoming  evident  that  the  comparatively  limited 
areas  of  the  best  coking  coals  are  being  rapidly  exhausted,  the 
question  of  securing  the  best  means  of  manufacturing  coke  from 
the  secondary  or  dry  coals  is  a  pressing  one,  deserving  the  earnest 
attention  of  the  coke  manufacturers  who  may  be  required  to  use 
this  class  of  coals. 

As  the  regions  of  the  first-class  coking  coals  become  more 
reduced  in  area  on  the  one  side,  with  the  expansion  of  the  use  of 
coke  on  the  other,  it  follows  that  the  increase  of  coke  demanded 
by  the  iron  and  steel  manufacturers  must  be  supplied  mainly 
from  the  coals  of  Section  3.  Some  investigations  and  tests  have 
been  made  in  the  use  of  retort  coke  ovens  in  coking  these  coals, 
which  so  far  have  afforded  assurance  of  the  best  results  in  coke 
from  these  secondary  coking  coals.  The  chief  element  retarding 
the  introduction  of  these'  vertical  coke  ovens  consists  in  the  large 
capital  required  in  establishing  a  plant  of  these  ovens,  with  or 
without  by-product-saving  auxiliary.  There  would  also  be  an 
added  expense  in  mining  the  coal  in  the  thin  beds  of  this  section, 
with  the  added  cost  of  disintegrating  and  washing  the  coal  pre- 
paratory to  charging  it  into  the  ovens.  Some  compensation  is 
afforded  in  this  locality  in  the  reduced  railroad  freight  eastwards. 

Section  4.  The  coals  embraced  in  this  section  are  very  dry, 
holding  only  15  to  20  per  cent,  of  volatile  combustible  matter,  and 
requiring  special  oven  treatment.  It  is  situated  mainly  along  the 
eastern  border  of  the  Appalachian  field,  from  Northern  Pennsylvania 
to  Southern  Virginia.  It  has  several  outlying  and  detached  fields, 
such  as  the  Blossburg,  Ly coming,  Broad  Top,  Cumberland,  etc. 

There  are  some  notable  additions  to  the  outer  edge  dry  coals. 
One  of  these  is  found  at  Johnstown,  Pennsylvania,  where  the  coals 
contain  only  16  to  19  per  cent,  of  volatile  matter,  and  although 
located  in  the  third  section  of  medium  coking  coals  they  really 
belong  to  the  fourth  section  of  dry  coals.  From  its  geographical 
position  westwards,  its  coal  should  inherit  at  least  25  per  cent,  of 
volatile  matter,  but  it  is  a  remarkable  fact  that  a  broad  belt  of 
this  exceptional  dry  coal  is  found  in  this  inner  section  of  the  Appa- 
lachian field.  Its  extremities  northeast  and  southwest  have  not 
been  defined. 

For  the  proper  treatment  of  this  section  of  extremely  dry  coals 
the  narrow  vertical  oven  must  be  used.  The  coal  will  also,  in 
most  instances,  require  preparation  by  disintegration,  in  separating 
slates  and  pyrites,  and  in  many  cases  by  washing. 

In  this  connection,  a  very  marked  example  of  the  effects  of 
coking  Blossburg  coal  in  beehive  and  Semet-Solvay  ovens  has 


TREATISE  ON  COKE  395 

come  to  notice.  In  the  round  oven  this  dry  coal  affords  61  per 
cent  of  marketable  coke.  In  the  Semet-Solvay  oven  it  yields 
78  per  cent,  of  large  coke.  Samples  of  each  were  tested  in  the 
laboratory  for  resistance  to  hot  carbon  dioxide.  A  few  grains  of 
each  were  placed  in  a  test  tube,  and  submitted  to  the  action  of 
a  stream  of  hot  carbonic-acid  gas,  for  equal  periods  of  time,  with 
the  following  results: 

LEFT  AFTER  TREAT-    Loss  AS 
MENT  WITH  CO2          CO 

Semet-Solvay 88 . 8  11.2 

Blossburg 65.4  34 . 6 

These  tests  indicate  the  very  wide  difference  in  the  hardness 
of  the  body  of  the  coke  and  its  property  of  resisting  the  dissolving 
agency  of  carbon  dioxide,  such  as  would  be  encountered  in  a  blast 
furnace.  The  CO  column  shows  more  than  three  times  the  prob- 
able loss  in  the  horizontal-oven  coke  above  the  Semet-Solvay 
oven  coke. 

The  difference  in  product  in  these  ovens  is  quite  large,  the 
vertical  oven  affording  an  increase  of  seventeen  units  of  coke,  or 
22  per  cent,  increase  in  product  over  the  beehive  oven.  This 
increase  contributes  to  the  reduction  of  the  volume  of  impurities 
to  the  sum  total  of  the  coke. 

It  may  therefore  be  accepted  as  a  general  principle  in  the 
treatment  of  these  dry  coals  that  the  quick  and  superior  heat  in 
the  retort  ovens  produces  the  hardest-bodied  coke  with  an  increased 
quantity  of  it. 

The  Connellsville  coke  made  in  beehive  and  Otto-Hoffman 
ovens  gave,  from  a  similar  test,  the  following  results: 

LEFT  AFTER  TREAT-    Loss  AS 
MENT  WITH  CO2  CO 

Beehive  Connellsville  coke 91. 0  9.0 

Otto-Hoffman 94 . 5  5.5 

As  a  standard  for  comparison,  anthracite,  which  is  a  natural 
coke,  gave  the  following  result: 

LEFT  AFTER  TREAT-    Loss  AS 

MENT  WITH  CO2  CO 

Anthracite 96 . 0  4.0 

The  Connellsville  coke  made  in  beehive  ovens,  as  well  as  the 
portion  made  in  Otto-Hoffman  ovens,  is  best  qualified  by  hardness 
of  body  to  resist  destructive  dissolution  in  blast-furnace  opera- 
tions. This  assures  the  economy  of  fuel  per  ton  of  pig  iron  made, 
•and  the  further  advantage  of  increased  output. 

In  the  West,  the  newer  coal  deposits  afford  occasional  areas  of 
good  coking  coals.  The  states  of  Colorado  and  Wyoming  have 
shown  considerable  progress  in  the  production  of  good  qualities 
of  metallurgical  cokes.  The  gradual  debituminization  of  the  coals 
eastwards  has  been  noticed  very  fully  in  Chapter  I. 


396  TREATISE  ON  COKE 

An  examination  of  the  geological  map  will  show  the  general 
contour  of  the  eastern  edge  of  the  great  Appalachian  coal  field. 
It  will  be  noted  that  this  eastern  contour  line  maintains  a  certain 
parallelism  with  the  old-time  Atlantic  shore  line  of  this  portion 
of  the  North  American  Continent.  The  intense  dynamic  thrust 
westwards  in  the  states  of  Kentucky,  Tennessee,  and  Alabama, 
with  the  subsequent  erosion  along  their  eastern  border,  has  removed 
the  region  of  the  dry  coals,  and  conferred  on  their  remaining  coals 
a  medium  quality  between  the  bituminous  coals  of  the  west  and 
the  dry  coals  on  the  eastern  borders. 

With  these  well-defined  areas  of  coals  that  can  be  coked,  the 
coke  manufacturer  can  decide  three  important  conditions  in 
selecting  a  location  for  his  plant:  (1)  In  which  of  these  sections 
will  he  establish  his  coking  plant?  (2)  What  type  of  coke  oven 
will  be  best  adapted  to  producing  the  best  possible  metallurgical 
coke?  (3)  Will  it  be  profitable  in  making  coke  to  save  the 
by-products:  the  tar,  and  ammonia  sulphate? 

It  may  be  helpful  in  determining  the  location  of  the  coke 
plant,  with  the  type  of  oven  to  be  used,  to  submit  the  following 
considerations : 

If  possible,  the  manufacturer  of  coke  should  locate  his  plant  in 
the  best  coking-coal  belt.  This  assures  the  best  product  of  coke, 
and  removes  any  suspicions  as  to  its  quality;  to  be  liable  to  be 
called  on  to  defend  the  character  of  coke  made  in  localities  not 
well  known,  or  not  having  the  quality  of  its  coke  assured,  adds 
considerable  worry  to  the  duties  of  the  manufacturer. 

It  will  be  found,  on  careful  consideration,  that  the  difference 
in  the  price  per  acre  is  not  a  vital  element  of  discouragement  in 
shaping  a  decision.  For  instance,  the  best  coking  coal  land  costs 
now  $600  to  $1,000  per  acre.  An  acre  of  this  coal  bed,  7^  feet 
thick,  will  afford  an  output,  with  careful  mining,  of  12,000  net 
tons  of  coal.  The  mining  of  this  coal,  under  existing  conditions 
in  the  Connellsville  field,  costs  about  25  cents  per  net  ton.  The 
coal  requires  no  disintegration  or  washing. 

PER  NET  TON 

The  royalty  on  coal,  at  $1,000  per  acre,  is    $   .0833 

Mining  coal .  3000 

Total $   .  3833 

Second-class  coking  coal  can  be  purchased  for  $50  per  acre 
for  the  coal  bed  alone.  Assuming  the  thickness  to  be  the  same, 
7|  feet,  affording  12,000  net  tons  of  coal  per  acre,  the  cost  will 
be  as  follows: 

PER  NET  TON 

Royalty  on  coal $    .  0041 6 

Mining 50000 

Total..  $   .50416 


TREATISE  ON  COKE  397 

The  difference  is  $0.121  per  net  ton  or  $1,452  per  acre  in  favor 
of  the  first  quality.  But  the  difference  in  cost  is  $950,  against 
the  best  coal,  having  still  in  its  favor  $502  per  acre,  to  cover 
interest  on  the  increased  investment. 

Again,  supposing  that  the  second  quality  of  coking  coal  requires 
disintegrating  and  washing,  this  will  add  5  to  8  cents  per  ton 
usually,  or  at  least  $600  per  acre,  making  the  ultimate  difference, 
in  this  case,  equal  to  $1,102  in  favor  of  best  quality  of  coking 
coal.  It  is  therefore  evident  that  the  best  qualities  of  coking 
coals,  commanding  the  higher  price,  are,  under  full  consideration, 
the  cheapest  in  the  end. 

In  the  thin  beds  of  the  third  section  of  coals  the  difference  in 
ultimate  cost  would  be  still  greater,  as  the  increased  cost  of  mining 
and  mine  ways  would  have  to  be  considered. 


COMPARISON  OF  DIFFERENT  TYPES  OF  OVENS 

In  the  selection  of  coke  ovens  for  coking  the  several  qualities 
of  coals,  the  table  on  page  398,  which  gives,  approximately, 
the  cost  and  output  of  each  type  of  oven,  will  be  found  helpful. 
This  table  is  believed  to  be  approximately  correct,  but  with  the 
varying  cost  of  materials  and  labor,  as  well  as  local'conditions,  no 
fixed  estimate  of  the  cost  of  plants  of  coke  ovens  should  be  sub- 
mitted. The  sure  method  of  learning  the  cost  is  by  direct  appli- 
cation to  the  companies  or  individuals  engaged  in  the  construction 
of  coke-oven  plants. 

It  may  also  be  submitted,  in  explanation  of  this  table, 
that  the  comparative  standard  of  annual  production,  in  market- 
able coke,  has  been  fixed  at  118,800  net  tons.  This  is  about 
the  yearly  product  of  two  banks  of  Otto-Hoffman  coke  ovens 
of  60  ovens  each. 

Column  (a)  gives  the  estimated  costs  of  these  coke  ovens. 
Column  (6)  shows  the  cost,  per  oven,  of  the  exhaust,  condensing, 
and  scrubbing  plant.  Column  (c)  gives  the  total  cost  per  oven, 
including,  where  used,  the  by-products-saving  plant.  Column  (d) 
gives  the  average  daily  product  of  marketable  coke  from  each 
type  of  coke  oven.  Column  (e)  gives  the  number  of  each  kind  of 
oven  to  produce  118,800  net  tons  of  coke  per  year.  Column  (/) 
gives  the  total  cost  of  each  coking  plant.  Column  (g)  shows  the 
amount  of  labor  and  materials  to  maintain  the  works  in  good  con- 
dition, estimated  at  5  per  cent,  on  investment.  This  charge  is 
designed  to  afford  a  fund  to  make  the  necessary  repairs  during 
the  20  years'  life  of  the  plant.  Column  (h)  distributes  this  interest 
sum  over  each  ton  of  coke  made.  Column  (i)  exhibits  the  pro- 
portion of  the  cost  of  sinking  the  whole  plant  in  20  years.  It  is 
estimated  that,  during  this  period,  2,376,000  net  tons  of  coke 
shall  have  been  made.  Column  (k)  gives  the  cost  of  labor  in 


398 


TREATISE  ON  COKE 


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TREATISE  ON  COKE  399 

making  coke  and  saving  the  by-products.  Column  (/)  shows  the 
tptal  cost  per  net  ton  of  coke  made;  it  embraces  the  costs  in  col- 
umns (h),  (i),  and  (&).  Column  (m)  gives  the  percentage  of  coke 
which  each  type  of  oven  produces.  Column  (n)  gives  the  value 
of  the  by-products  of  tar,  ammoniacal  liquor  or  sulphate  of 
ammonia,  and  gas  per  ton  of  coke.  This  value  is  considerably 
under  the  usual  sums  estimated  for  these  products.  But  it  is 
submitted  that  the  value  of  by-products  at  the  works  and  in  a 
more  or  less  distant  market  differs  materially.  It  may  also  be 
noted  that  these  products  have,  in  common  with  all  others,  their 
variations  in  market  value.  Column  (o)  shows  the  saving  of  coal 
by  increased  percentage  of  product.  Column  (p)  gives  the  ulti- 
mate cost  per  net  ton  of  coke  produced. 

In  all  the  calculations  it  has  been  assumed  that  the  best  coking 
coals  have  been  used.  No  charges  have  been  made  for  the  prepa- 
ration of  coals  that  require  crushing  and  washing.  No  patent- 
right  charges  have  been  embraced  in  these  columns.  In  making 
the  foregoing  comparisons,  no  credit  has  been  given  the  retort 
ovens  for  heat  supplied  for  making  steam,  or  for  surplus  gas  for 
lighting  purposes. 

The  entire  cost  of  coke  made  in  these  ovens  can  readily  be 
ascertained  by  taking  the  percentage  of  marketable  coke  produced 
by  each  type  of  oven,  as  given  in  column  (m).  For  instance,  the 
beehive  oven  yields  65  per  cent,  of  coke;  it  will,  therefore,  require 
Y/  =  1.538  tons  of  coal  to  make  1  ton  of  coke.  The  cost  of  the 
coal,  delivered  at  the  coke  ovens,  can  readily  be  learned  for  any 
locality.  The  ultimate  cost  in  column  (p)  added  to  the  cost  of 
the  amount  of  coal  to  make  1  ton  of  coke  will  give  the  absolute 
net  cost  of  1  net  ton  of  coke. 

The  table  on  page  400  has  been  furnished  by  the  United  Coke 
and  Gas  Company,  of  New  York  City. 

In  the  areas  of  the  best  coking  coals,  the  horizontal  types  of 
coke  ovens  will  probably  retain  their  places  of  usefulness.  The 
principles  involved  in  the  manufacture  of  metallurgical  coke  in 
these  ovens  are  undoubtedly  the  true  ones,  concentrating  the 
greatest  heat  at  the  crown  of  the  oven  and  graduating  it  down- 
wards toward  the  bottom  of  the  oven.  This  secures,  under  the 
moderate  pressure  of  the  charge  of  coal,  the  liberty  or  freedom 
of  the  mass  to  develop  cell  structure,  and  secures  the  deposit  of  a 
maximum  quantity  of  carbon  from  the  gases  evolved  in  coking 
as  they  pass  upwards  through  the  incandescent  portion  of  the 
charge,  glazing  it  with  this  deposit  of  pure  carbon. 

The  manual  labor  in  drawing  the  round  ovens  should  be 
removed,  as  it  is  exhausting  to  the  workmen  and  expensive  to 
the  manufacturer. 

In  the  determination  of  the  quality  of  coal  for  the  manufacture 
of  coke,  the  sure  method  is  to  have  a  sufficient  quantity  of  it 
coked  carefully  in  one  or  more  selected  types  of  coke  ovens.  The 


400 


TREATISE  ON  COKE 


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TREATISE  ON  COKE  401 

physical  properties  of  the  coke,  as  well  as  its  calorific  value  for 
blast-furnace  use,  can  be  accurately  ascertained  by  laboratory  tests. 

In  selecting  the  type  of  oven  for  coking  any  of  the  several 
qualities  of  coal,  it  will  be  well-directed  economy  to  have  this 
work  performed  under  the  care  of  an  expert  in  the  manufacture 
of  coke,  as  not  only  the  type  of  oven  is  to  be  selected  as  best  adapted 
for  coking  the  coal,  but  the  proper  dimensions  of  the  several  parts 
of  the  oven  chosen  are  to  be  determined. 

Attention  is  invited  to  the  ingenious  plant  of  Doctor  Otto  for 
obtaining  the  by-products  from  the  beehive  type  of  horizontal 
ovens.  Doctor  Terne,  in  his  paper,  calls  earnest  attention  to  the 
large  waste  in  the  United  States  of  this  valuable  manure  in  the 
manufacture  of  coke.  With  the  42,000  of  these  ovens  now  in 
operation,  a  large  field  is  invitingly  opened  to  inventors  to  devise 
a  practical  plan  for  saving  these  by-products  and  augmenting  the 
oven  heat  by  the  returned  gas. 

The  products  of  Doctor  Otto's  round  oven  are  shown  to  be 
equal  to  any  of  the  retort  ovens,  75  per  cent,  coke,  1  per  cent, 
ammonia  sulphate,  and  2J  to  3  per  cent,  of  tar.  The  cost  of  this 
oven  has  not  been  given.  From  its  plain  construction  this  cost 
would  be  small,  as  compared  with  the  vertical  ovens. 

Advisability  of  Saving  By-Products. — An  important  supple- 
mentary consideration  for  the  coke  manufacturer  is  presented  in 
the  question, 'in  connection  with  the  use  of  retort  coke  ovens, 
whether  it  will  be  profitable  to  invest  the  large  additional  sum 
required  in  the  conduits  and  condensing  plant  for  the  saving  of 
the  by-products  of  tar  and  sulphate  of  ammonia.  The  approxi- 
mate cost  of  the  auxiliary  plant  for  saving  these  by-products  is 
given  in  the  table  on  page  398. 

In  approaching  this  inquiry,  it  may  be  submitted  that  hitherto 
considerable  prejudice  has  been  manifested  against  the  quality  of 
coke  made  in  retort  coke  ovens,  in  which  the  by-products  were 
saved.  Sufficient  evidence  has  not  been  developed  in  this  country 
to  settle  this  matter  by  accurate  tests  in  blast-furnace  use,  but  on 
the  continent  of  Europe  it  is  alleged  that  at  present  no  discrimi- 
nation is  made  by  metallurgists  against  this  quality  of  the  retort 
oven  coke,  provided  that  it  is  made  in  a  careful  manner. 

There  does  not  appear  any  evident  reason  why  the  exhausting 
of  the  gases  in  coking  should  deteriorate,  in  a  marked  degree,  the 
quality  of  the  coke,  but  it  should  on  the  other  side,  by  increasing 
its  hardness,  more  than  compensate  for  any  loss  in  the  exhaustion 
of  the  gases. 

Market  for  Tar  and  Ammonium  Sulphate. — Mr.  Wagner,  of 
Darmstadt,  has  recently  shown  that  ammonium  sulphate  is  supe- 
rior to  Chili  saltpeter  or  guano  as  a  fertilizer  in  agricultural  uses. 
In  the  United  States,  there  are  approximately  300  millions  of 
acres  of  land  under  cultivation.  Perhaps  one-third  of  these 


402  TREATISE  ON  COKE 

retain  much  of  the  normal  richness  and  will  not  at  present  require 
concentrated  manures.  It  is  further  assumed  that  one-third  will 
be  manured  in  the  usual  way  with  barnyard  and  compost  manures, 
and  that  50  millions  of  acres  will  be  manured  by  native  and 
imported  guano,  phosphates,  nitrates,  and  ammonium  sulphate, 
leaving  50  millions  of  acres  to  be  supplied  mainly  by  native 
ammonium  sulphate.  This  will  require  160  pounds  of  this  salt  or 
its  equivalent  to  fertilize  1  acre  in  an  ample  manner.  For  the 
50  millions  of  acres,  4  millions  of  tons  of  this  manure  will  be 
required,  but  it  is  not  probable  that  this  will  be  used  by  the 
agriculturists  for  some  time  to  come. 

Reducing  the  probable  quantity  of  this  concentrated  manure 
that  may  be  required  to  2  millions  of  tons  per  year,  it  will  readily 
appear  that  the  product  of  ammonium  sulphate,  during  the  year 
1893,  did  not  greatly  exceed  60,000  tons,  leaving  1,940,000  tons 
to  be  provided  for.  Should  the  coke  ovens  of  the  United  States 
be  changed  to  save  this  by-product,  from  the  10  millions  of  tons 
of  coke,  it  would  afford  1  million  of  tons  of  ammonium  sulphate, 
leaving  a  deficit  of  940,000  tons.  The  outlook  for  a  market  for 
ammonium  sulphate  is  well  assured.  It  may  be  noted,  however, 
that  in  competition  with  other  manures  its  price  will  be  held  at 
a  maximum  not  greatly  exceeding  3  cents  per  pound. 

The  chemical  works  and  tar  distilleries  at  Philadelphia,  Buffalo, 
Cleveland,  and  Chicago  are  prepared  to  purchase  tar  and  ammoni- 
acal  liquor.  -  These  companies  usually  own  and  furnish  iron  tank 
cars  for  freighting  these  liquid  products  from  the  coke  works  to 
the  chemical  plants.  Some  of  the  companies  are  prepared  to 
receive  the  tar  during  all  the  months  of  the  year;  others  require 
the  coke  manufacturer  to  store  the  tar  in  great  tanks  during  the 
winter  months. 

It  becomes  an  important  consideration,  in  this  connection, 
how  far  the  coke  manufacturer  should  advance  these  distillates 
in  order  to  secure  the  maximum  profit  from  their  sale  in  market. 
It  is  evident  that  tar,  as  it  is  condensed  from  the  gases  at  the 
coke  ovens,  can  be  shipped  with  the  most  economy  in  its  crude 
state,  provided  that  it  can  be  marketed  continuously  throughout 
the  year.  Boiling  it  to  pitch  involves  extended  chemical  opera- 
tions, in  securing  the  utmost  economy. 

A  companion  investigation  relates  as  to  whether  the  coke 
manufacturer  will  dispose  of  the  ammoniacal  liquor,  at  the  strength 
usually  required,  2°,  2.5°,  and  2.8°  Twaddell,  or  advance  it  to 
ammonium  sulphate,  either  as  an  agricultural  manure  or  for 
chemical  uses.  The  latter  involves  an  ammonia-factory  addition 
to  the  condensing  plant,  with  expert  chemical  supervision. 

If  the  market  or  chemical  works  is  not  at  a  great  distance 
from  the  coke  works,  it  would  in  most  cases  conduce  to  economy 
to  ship  the  ammoniacal  liquor  in  the  moderate  strength  usually 
required  by  the  chemical  companies.  If  the  market  is  quite 


TREATISE  ON  COKE 


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404  TREATISE  ON  COKE 

distant,  it  becomes  a  question  of  the  cost  of  transportation  in  ship- 
ping the  liquor  or  advancing  it  to  the  ammonium  sulphate.  In 
this  latter  case  it  is  evident  that  the  manufacture  of  ammonium 
sulphate  at  the  coke  ovens  would  be  the  true  economy,  as  the 
freight  charges  on  the  ammoniacal  liquor  would  be  quite  large. 

It  may  be  noted  in  this  inquiry  that  it  requires  3,520  gallons 
of  2°  Twaddell  of  the  liquor  to  make  1  net  ton  of  the  sulphate  of 
ammonium,  composed  as  follows: 

59.410  per  cent.  5O3  (sulphuric  acid) 
25.060  per  cent.  NH.<  (ammonia) 

.018  per  cent.  Fe2O^  (ferric  oxide) 
15.512  per  cent.  H.2O  (water) 


100 . 000 

About  8  per  cent,  of  ammonia  is  lost  in  the  manufacture  of 
ammonium  sulphate. 

It  may  be  noted  here  that  the  cost  of  gas  liquor  will  change 
with  the  size  of  the  plant  and  the  quality  of  the  coal  used  in 
making  coke.  Coals  with  large  volumes  of  volatile  matter  will 
usually  produce  the  largest  amounts  of  liquor  and  gas,  which  can 
be  sold  at  reasonable  profits,  reducing  the  cost  of  the  coke.  The 
selling  price  of  the  salt,  ammonium  sulphate,  fluctuates  from 
$50  to  $65  per  ton  in  the  city  markets. 

In  the  larger  coke  works,  producing  by-products,  this  inquiry 
broadens  in  its  general  aspect,  involving  two  important  consider- 
ations; first,  whether  it  is  more  advantageous  to  supplement  the 
condensing  plant  with  an  ammonia  factory  and  tar-boiling  plants, 
or  second,  to  invite  some  established  chemical  company  to  erect 
at  the  coke  works  a  chemical  plant  to  receive  and  treat  the  crude 
by-products,  advancing  them  to  tar  and  ammonium  sulphate, 
with  resultant  distillates,  thus  economizing  the  freight  expenses 
in  handling  these  products. 

There  are  some  difficulties  in  establishing  an  equitable  basis 
for  regulating  the  prices  of  the  crude  products.  This  standard 
might  be  founded  on  the  market  value  of  the  crude  materials,  or 
on  their  finished  products,  less  the  freights  in  either  condition, 
to  the  nearest  reliable  markets. 

On  the  whole,  it  would  appear  that  a  direct  reference  of  the 
value  of  these  by-products  in  the  crude  state,  in  the  tanks  at  the 
works,  would  prove  the  more  practical.  The  rates  to  be  paid 
could  be  determined  by  their  market  values,  deducting  the  freight 
thereto  at  such  stated  intervals  as  would  be  equitable  to  the 
producer  and  manufacturer. 

An  experiment  has  recently  been  made  to  utilize  benzole  in 
enriching  illuminating  gas.  So  far  the  results  appear  to  be  very 
encouraging.  Should  this  new  application  prove  successful,  it 
would  add  materially  to  the  revenue  of  the  coke  manufacturer, 


TREATISE  ON  COKE  405 

from  the  tar  by-product.  It  has  been  found  that  in  tar  boiling, 
about  2  gallons  of  this  distillate  can  be  secured  in  the  making  of 
1  ton  of  coke.  The  benzole  is  estimated  to  be  worth  13  cents 
per  gallon. 

In  some  portions  of  the  United  States  and  Canada,  briqueting 
coal  waste  and  bog  materials  has  been  installed  in  a  small  way. 
Should  these  industries  continue  to  expand,  a  large  home  market 
would  be  secured  for  the  tar  products  of  the  retort  coke  ovens. 
Tar  is  also  coming  into  a  liberal  use  in  the  manufacture  of  roofing 
materials. 


CHAPTER  XI 


THE  FUEL  BRIQUETING  INDUSTRY 

In  Europe,  during  the  past  quarter  of  a  century,  the  briquet- 
ing  industry  has  been  developed  until  at  present  it  has  impressed 
its  importance  among  the  world's  industries.  In  this  manu- 
facture, the  lower  qualities  of  combustible  fuels  are  utilized, 
placing  them  in  compact  forms  for  manufacturing,  marine,  rail- 
road, and  domestic  uses.  The  expansion  of  this  industry,  with 
its  increasing  value  in  economizing  waste  products,  has  been 
brought  into  notice  in  the  United  States  mainly  through  the 
agencies  of  the  consular  service.  The  combustible  elements  used 
in  this  manufacture  consist  of  slack  coal  or  screenings,  anthracite 
culm  or  dust,  coke  breeze,  lignite  coal,  charcoal  dust,  bog  turf, 
carboniferous  mud,  and  petroleum.  The  manufacture  consists  in 
pulverizing  these  elementary  materials  and  then  mixing  them 
thoroughly  with  the  necessary  bonding  matter,  consisting  chiefly 
of  coal  tar  or  pitch;  the  composition  is  then  pressed  into  several 
shapes  to  meet  the  consumer's  needs. 

Evidently,  this  industry  is  in  its  most  advanced  condition  in 
countries  inheriting  large  areas  of  inferior  qualities  of  coals,  or 
with  broad  localities  of  peat  bogs,  and  where  fuel  is  high  priced. 
It  has  also  been  largely  developed  in  the  countries  in  which  retort 
coke  ovens  are  in  large  use,  producing  coal  tar  as  one  of  the  chief 
by-products,  which  can  be  used  in  its  crude  state  or  boiled  to 
pitch,  thus  contributing  the  important  bonding  material  in  the 
manufacture  of  briquets.  It  may  be  noted,  in  this  connection, 
that  in  most  of  these  countries  producing  briquets,  the  price  of 
good  coal,  especially  for  domestic  use,  is  nearly  prohibitory,  ranging 
from  $3  to  $20  per  ton.  To  insure  a  market  for  the  briquet  prod- 
ucts, the  price  must  be  considerably  under  that  of  good  coal  in 
the  several  countries  in  which  briqueting  has  been  established. 

At  this  time  Germany  is  the  largest  producer  of  briquets,  and 
with  the  development  of  this  industry  there  have  been  invented 
many  varieties  of  briqueting  machines.  France,  Belgium,  Austria- 
Hungary,  Netherlands,  Norway,  and  Great  Britain  have  also 
taken  up  this  manufacture  with  much  energy  and  have  made 
hopeful  progress.  These  examples  of  the  economy  of  utilizing 
the  less  valuable  fuels  in  briquets  are  extending  the  industry  to 

406 


TREATISE  ON  COKE  407 

other  countries,  especially  to  those  having  large  deposits  of  the 
raw  materials  suitable  for  the  manufacture  of  briquets.  In  1882, 
4,000,000  metric  tons  of  briquets  were  produced;  it  is  now  esti- 
mated that  nearly  25,000,000  tons  are  produced,  or  almost  3  per 
cent,  of  the  total  product  of  coal  and  lignite. 

Fuel  briqueting  has  for  its  aim  the  accomplishment  of  the 
following  objects:  (1)  the  utilization  of  the  fine  material  una- 
voidably made  in  the  mining  and  handling  of  coal;  (2)  the  crea- 
tion of  a  good  hard  fuel  to  burn  practically  without  smoke  or 
odor;  (3)  the  concentration  of  the  greatest  number  of  heat  units 
into  the  smallest  space  practicable,  by  cleaning  and  compressing 
material  of  inferior  heating  value. 

In  the  mining  of  coal,  a  large  proportion  of  the  output  of  a 
mine  is  often  necessarily  dust,  slack,  or  culm,  of  which  a  certain 
amount  is  wasted.  In  the  case  of  coking  coals,  the  slack  is  gen- 
erally charged  into  ovens,  but  anthracite  dust  is  usually  wasted. 

To  appreciate  the  advantage  of  using  fuels  that  burn  without 
smoke  or  odor,  one  should  contrast  some  American  cities  with 
those  of  Germany.  The  dense  trailing  clouds  of  smoke  from  mill 
and  factory  chimneys,  which  are  so  familiar  a  sight  in  Pittsburg 
and  other  cities  in  the  United  States  extensively  burning  raw 
coals  rich  in  bitumen,  are  said  to  be  rarely  seen  in  those  sections 
of  Germany  in  which  briquets  are  largely  used.  In  this  latter 
country,  the  indiscriminate  shoveling  of  raw  bituminous  coal  into 
steam  and  other  furnaces  is  considered  an  ignorant  and  wasteful 
proceeding. 

The  third  object — that  of  obtaining  concentrated  fuel — is  one 
not  to  be  overlooked  when  fuel  is  to  be  transported  long  distances 
before  it  is  used,  and  also  when  storage  room  is  limited.  Many 
coals  require  washing  to  remove  impurities  before  coking,  and  a 
similar  process  is  sometimes. advantageously  employed  in  briquet- 
ing  processes  to  clean  the  material  used. 

The  characteristics  desirable  in  fuel  briquets  are  enumerated 
in  the  following  specifications  issued  by  the  French  Navy  and  the 
Belgian  State  Railway:  (1)  the  briquet  must  be  hard,  homo- 
geneous in  density  and  size,  only  very  slightly  hygroscopic,  and 
should  burn  almost  without  smoke  or  odor;  (2)  the  dust  and 
breakage  caused  by  handling  and  transportation  should  not  exceed 
5  per  cent.;  (3)  the  specific  gravity  should  not  be  less  than  1.19; 
(4)  the  briquet  should  ignite  readily,  burn  with  a  cheerful  flame, 
and  retain  its  shape  until  completely  burned;  (5)  the  ash  should 
not  exceed  9  per  cent,  and  the  evaporation  results  should  at  least 
equal  those  of  the  best  lump  coal,  from  the  screenings  and  dust 
of  which  the  briquet  was  made. 

Briquets  are  made  in  various  sizes  and  shapes,  some  of  which 
are  shown  in  Fig.  1.  The  large  briquets  in  the  background  are 
for  factory,  marine,  and  locomotive  use,  and  are  broken  before 
being  fired,  while  the  others  are  used  whole;  the  scale  gives  an 


408  TREATISE  ON  COKE 

idea  of  their  dimensions.  The  Zeitz  and  the  briquets  between 
them  are  for  factory,  and  the  smaller  ones  in  the  foreground  for 
domestic,  use.  They  are  made  in  sizes  ranging  from  over  20 
pounds  each  to  a  size  that  takes  several  to  make  a  pound.  Indus- 
trial briquets  are  usually  of  a  square  or  oblong  form,  convenient 
to  be  closely  packed  or  built  up  into  a  pile  like  bricks.  They  are 
generally  loaded  on  cars  for  transportation,  packed  closely,  and 
are  similarly  stored  around  works,  particularly  when  intended  to 
be  kept  for  a  time,  or  when  large  storage  capacity  is  not  available. 
In  connection  with  the  storage  of  briquets,  it  is  of  importance  to 
note  that  there  is  practically  no  danger  from  spontaneous  com- 
bustion, as  is  sometimes  the  case  with  run-of-mine  bituminous 
and  other  coals  when  stored.  Each  briquet  generally  bears  the 
initials  or  trade  mark  of  the  company  by  which  it  is  produced, 


FIG.  1.     BRIQUETS  OF  DIFFERENT  FORMS 

so  that  in  case  of  any  defect  in  quality  the  inferior  briquet  can  be 
readily  traced  to  its  source  of  production.  When  burned  whole, 
they  usually  are  consumed  slowly  and  give  out  a  steady,  moderate 
heat  for  a  long  time;  when  it  is  desired  to  quicken  or  intensify 
the  flame,  they  are  broken  up,  and  in  this  condition  are  especially 
adapted  to  flue  or  tubular  boilers,  sugar  evaporating,  smelting  and 
annealing  furnaces,  in  glass  manufacture,  or  in  porcelain  and 
cement  factories — wherever,  in  fact,  a  fuel  capable  of  producing 
a  long,  fierce  flame  is  desirable. 

Mr.  Robert  Schorr  states,  in  a  paper  on  Fuel  and  Mineral 
Briqueting,  read  before  the  American  Institute  of  Mining  Engi- 
neers, that  "of  the  many  shapes  used,  the  prismatic  shape  with 
rounded  edges  is,  as  a  rule,  the  most  popular.  Heavy  blocks 
allow  of  a  large  output  with  a  comparatively  small  investment, 
and  they  are  very  convenient  for  storage.  However,  they  have 
the  disadvantage  of  large,  smooth  surfaces,  and  unless  broken  up 


TREATISE  ON  COKE  409 

prior  to  being  fed  into  a  furnace  they  are  apt  to  smother  the  fire 
and  choke  the  draft,  a  circumstance  that  is  nearly  always  the 
case  with  a  poor  grade  of  coal  or  one  that  has  been  too  finely  ground. 
To  facilitate  the  breaking  up  of  the  large  blocks,  channels  are 
pressed  into  the  bricks,  or  they  are  perforated  in  one  operation 
while  being  formed  in  the  press.  This  construction  offers  the 
advantage  of  a  better  air  circulation.  The  manufacture  of  tubu- 
lar, or  polygonal,  briquets  is  very  limited. 

The  French  Navy  estimates  820  kilograms  of  fuel  blocks  per 
cubic  meter  of  bunker  capacity  (more  than  51  pounds  per  cubic 
foot),  i.  e.,  10  per  cent,  more  as  compared  with  the  storage  of 
lump  coal.  The  losses  in  dust  seldom  exceed  4  per  cent.,  while 
the  best  Welsh  coal  averages  about  30  per  cent.,  and  in  stormy 
weather  nearly  50  per  cent.,  dust,  which  reduces  the  stored  heat- 
ing capacity  very  considerably.  Railroad  transportation,  even  for 
long  distances,  causes  generally  not  more  than  3  per  cent,  of  dust. 
Cylindrical,  ball,  and  egg-shaped  briquets  give  still  less  dust  and 
breakage,  but  they  are  wasteful  in  space.  Their  shape  insures  a 
good  air  circulation  and  consequently  a  complete  combustion. 

The  specific  gravity  of  briquets  varies  with  the  material  and 
pressure  employed,  and  is  usually  as  high  as  that  of  the  fuel  from 
which  they  have  been  made,  i.  e.,  from  1.1  to  1.4. 


COMPOSITION  OF  BRIQUETS 

Briquets  may  be  made  of  any  of  the  following  materials:  coal 
slack,  screenings,  or  dust;  anthracite  screenings  or  culm;  coke 
breeze  or  small  coke;  lignite  coal;  charcoal;  peat  or  turf;  carbon- 
iferous mud;  petroleum. 

Coal-Slack,  Screenings,  or  Dust  Briquets. — Among  the  princi- 
pal carboniferous  materials  used  in  the  manufacture  of  briquet 
fuels  are  coal  slack,  screenings,  and  dust.  Mr.  Schorr  states  that 
"the  size  and  cleanness  of  the  fuel  are  important  items.  The 
grains  should  not  be  larger  than  J  inch  and  not  less  than  -3-2-  inch 
in  size  to  make  a  good-burning  briquet.  If  the  coal  is  ground  too 
fine  it  will  make  a  very  handsome-looking  briquet,  but  it  will 
not  ignite  as  readily  and  it  takes  a  strong  draft  to  burn  it  suc- 
cessfully. The  ash  content  should  not  exceed  6  per  cent.  If 
greater  than  this  amount,  the  coal  should  be  washed  by  water 
or  treated  in  a  pneumatic  separator  in  order  to  remove  the  excess 
of  ash.  If  presses  with  solid  resistance  are  used,  the  raw  material 
must  be  of  a  commercial  dry  ness,  but  in  open-mold  presses  a 
large  amount  of  moisture  may  be  present." 

Slack  from  coals  rich  in  bitumen  will  work  into  briquets  with 
an  addition  of  2  or  3  per  cent,  of  pitch,  while  leaner  grades  may 
require  6  to  8  or  even  10  per  cent. ;  the  last  proportion  is  sufficient 


410  TREATISE  ON  COKE 

at  times,  when  the  cost  of  pitch  is  high,  to  render  such  coal  unprofit- 
able for  briquet  purposes.  Briquets  made  from  bituminous  slack, 
although  not  smokeless,  are  more  nearly  so  than  ordinary  bitu- 
minous coal.  When  burned  in  locomotives  or  any  well-constructed 
boiler  or  other  furnace  with  a  good  draft,  they  create  qnly  a  thin 
translucent  mist  that  contains  relatively  little  soot,  and  is  very 
different  from  the  inky  clouds  that  roll  up  from  many  factory 
chimneys  where  soft  coal  is  shoveled  indiscriminately  into  the 
furnaces.  The  one  notable  defect '  of  such  briquets  is  that  the 
mineral  pitch,  which  is  used  as  a  binder,  contains  more  or  less 
creosote;  this  renders  dust  and  fumes  from  such  fuel  acrid  and 
sometimes  irritating  to  the  skin  when  confined  in  a  close,  hot 
boiler  room. 

In  the  manufacture  of  briquets  from  coal  slack,  screenings,  or 
dust,  the  material  is  reduced  by  a  disintegrator  to  fine  particles 
when  necessary.  The  binder  is  then  added,  and  when  pitch  is 
used  as  a  bonding  material  the  mixture  is  ready  for  the  heater. 
The  most  common  way  of  mixing  is  the  dry  method,  by  which  the 
pitch  is  ground  up  and  added  to  the  coal  in  a  dry  state.  The  com- 
bined mass  of  coal  and  pitch  is  then  placed  in  a  heater  in  which 
the  pitch  is  melted;  in  some  instances,  the  heater  is  a  drying  appa- 
ratus as  well,  removing  any  water  that  may  be  in  the  coal.  After 
treatment  in  this  machine  the  hot  mass  passes  to  the  presses, 
where  it  is  rapidly  pressed  into  the  form  of  briquets. 

Anthracite-Screenings,  or  Culm,  Briquets. — Anthracite  screen- 
ings, or  culm,  has  been  used  in  the  manufacture  of  briquets.  In 
some  cases,  a  slight  mixture  of  bituminous  slack  coal  is  added  to 
reenforce  the  bonding  pitch.  Owing  to  the  cost  of  the  binder  and 
the  comparative  cheapness  of  the  coal,  anthracite  briquets  have 
never  been  a  commercial  success  to  any  great  extent.  At  such 
points  as  Chicago,  where  anthracite  is  transferred  from  boats  to 
railroad  cars,  or  at  seaboard  towns  where  large  amounts  are 
handled  and  much  fine  coal  made,  this  fine  material  is  sometimes 
briquet ed  for  lo'cal  use. 

Coke-Breeze,  or  Small-Coke,  Briquets. — In  the  manufacture  of 
coke  in  beehive  coke  ovens,  about  2  to  3  per  cent,  of  small  coke 
or  breeze  is  produced.  This  is  reduced  to  very  small  sizes  or  dust 
and  mixed  with  pitch  or  tar  in  the  usual  way.  Necessarily  this 
coke  breeze  must  be  washed  to  be  freed  from  the  ash  or  slate  asso- 
ciated with  it,  which  often  amounts  to  20  or  30  per  cent.  The 
manufacture  of  these  coke  briquets  is  very  trying  to  the  machinery, 
as  the  powder  is  very  sharp,  wearing  away  the  metal  of  the 
grinding  and  mixing  machinery  very  rapidly.  In  all  countries  in 
which  the  coke-making  industry  is  large,  an  inviting  opening  is 
presented  for  the  utilization  of  this  coke  waste  in  the  manu- 
facture of  coke  briquets.  The  briquets  made  from  coke  dust  are 
especially  desirable  for  domestic  uses,  as  they  are  almost  smokeless. 


TREATISE  ON  COKE  411 

Lignite  Briquets. — Lignite,  or  brown  coal,  is  a  very  important 
element  in  the  manufacture  of  briquets.  It  varies  in  its  value 
and  adaptability  for  briqueting  purposes  according  to  its  geologic 
age,  hardness,  and  the  percentage  of  water  that  it  contains.  A 
lignite  with  less  than  30  per  cent,  of  water  is  very  difficult  to  work 
by  the  usual  processes.  The  amount  of  moisture  in  lignite  fuel 
forms  the  key  to  the  whole  economic  briqueting  process.  The 
crude  brown  coal  is  brought  from  the  mine,  crushed  and  pulver- 
ized, and  then  dried  and  heated  with  the  proper  temperature  to 
develop  the  latent  bitumen  in  the  lignite  and  make  the  powdered 
mass  plastic  and  easy  to  mold,  under  heavy  pressure  between 
heated  iron  jaws,  into  a  hard,  clean  briquet,  with  a  glistening 
surface  and  sufficient  firmness  of  structure  to  stand  weather, 
transportation,  and  other  contingencies.  To  do  this  perfectly 
and  economically,  the  natural  lignite  should  contain,  as  it  comes 
from  the  mine,  approximately  enough  moisture  so  that  heating 
to  the  proper  temperature  for  pressing  will  evaporate  out  just 
sufficient  water  to  leave  it  at  the  proper  degree  of  moisture.  The 
ideal  proportion  is  about  45  per  cent,  of  water.  Considerable 
interest  attaches  to  lignite  as  a  briqueting  proposition  in  the  differ- 
ent countries,  as  it  is  an  inferior  fuel  direct  from  the  mine,  on 
account  of  its  tendency  to  rapidly  disintegrate  on  exposure  to 
the  air. 

Charcoal  Briquets. — In  the  countries  in  which  much  charcoal 
is  produced,  the  dust  made  in  its  manufacture  and  handling 
affords  a  most  excellent  and  pure  material  for  the  manufacture 
of  briquets.  The  usual  mode  of  preparation  is  quite  economical, 
and  the  binding  material  is  mixed  with  the  charcoal  dust  in  the 
usual  way.  These  charcoal  briquets  afford  the  purest  quality  of 
fuel  and  are  especially  adapted  for  supplying  heat  in  the  manu- 
facture of  iron  and  steel. 

Peat,  or  Turf,  Briquets. — The  bogs  in  which  peat  is  contained 
cover  extensive  areas  in  the  northern  temperate  latitudes,  both 
in  Europe  and  America.  In  Germany,  they  cover  nearly  11,583 
square  miles,  and  in  Ireland,  according  to  Snell,  they  cover  the 
tenth  part  of  the  country.  The  depth  is  very  variable,  but  is,  on 
an  average,  5.4  to  7.6  yards;  in  Ireland,  bogs  are  found  with  a 
depth  as  great  as  16.3  yards.  It  may  be  estimated  that  1  square 
mile  (2.59  square  kilometers)  5.4  yards  deep  will  give  about 
1,813,000  metric  tons  of  dried  peat;  hence,  it  will  be  seen  that  the 
amount  of  fuel  in  those  bogs  is  enormous.  Peat  is  organic  matter 
formed  from  mosses  and  other  minor  plants  that  have  been  sub- 
merged in  water  and  are  thus  preserved  in  the  bogs. 

As  a  material  for  fuel,  peat  ranks  "next  in  the  natural  order 
below  lignite,  in  that  it  is  of  similar,  but  much  more  recent,  geo- 
logical order,  contains  more  water,  is  but  slightly  carbonized,  and 
has  a  correspondingly  lower  thermal  value  than  lignite,  or  browrn 


412  TREATISE  ON  COKE 

coal.  The  task  of  converting  peat  into  serviceable  fuel  consists 
of  cleaning  the  material  of  roots  and  rubbish,  reducing  the  water 
to  a  smaller  percentage,  and  condensing  the  peat  in  volume  so 
that  its  thermal  value  shall  be  raised  to  practical  efficiency.  This 
is  done  by  various  methods,  which  may  be  grouped  under  three 
heads,  according  to  the  form  that  the  ultimate  product  is  to 
assume:  first,  compressed  peat,  with  or  without  the  admixture 
of  coal  dust  or  of  inflammable  matter;  second,  peat  coke;  and 
third,  briquets  made  by  compression,  with  or  without  heat,  of  the 
material  prepared  by  the  first  process. 

Peat  cut  from  the  bog  has  been  used  for  centuries  and  in  the 
ordinary  process  of  drying  the  material  is  cut  into  cubes  and  laid 
in  the  air,  where  most  of  the  water  held  between  the  fibers  soon 
leaches  out  by  gravity  or  evaporation.  Machine  peat,  which  is 
the  compacter  and  better  article,  has  come  into  use  within  recent 
times.  Two  principal  systems  are  distinguished  in  making  machine 
peat,  depending  on  the  treatment  of  the  raw  material  immediately 
upon  raising  it  from  the  bog.  One  plan  is  to  digest  the  peat  with 
the  addition  of  water  into  a  liquid  mud,  which  is  then  poured  into 
molds  in  the  open  air  and,  after  losing  some  of  its  water,  divided 
into  blocks  and  allowed  to  dry.  The  other  and  more  commonly 
employed  process  consists  of  grinding  or  mincing  the  peat  as  it 
comes  from  the  bog  into  a  soft,  plastic  mass,  which  is  then  made 
into  bricks  and  dried.  This  grinding  of  the  peat  is  to  better  pre- 
pare the  fibers  to  give  up  their  liquid  contents. 

One  of  the  important  improvements  of  recent  years  has  been 
attained  by  mixing  the  peat  pulp  as  it  passes  through  the  grind- 
ing machine,  with  other  inflammable  materials;  such  as,  bitu- 
minous coal  dust,  or  slack,  up  to  30  per  cent. ;  anthracite  culm, 
to  40  per  cent. ;  or  dry  sawdust,  to  15  per  cent.  These  dry  pulver- 
ized materials,  when  mingled  with  the  wet  peat,  not  only  greatly 
enhance  its  subsequent  value  as  fuel,  but  facilitate  the  drying 
process  and  render  it  tough,  dense,  elastic,  and  capable  of  being 
pressed  cold  into  briquets  of  high  quality.  But  by  far  the  most 
modern,  scientific,  and  rational  method  of  utilizing  peat  appears 
to  be  that  of  converting  it  into  coke  by  carbonization  in  retort 
ovens,  with  recovery  of  the  gas,  tar,  and  other  by-products  of  distil- 
lation. One  method  of  coking  peat  consists  in  carbonizing  the  peat 
in  closed  ovens  heated  by  burning  the  gases  generated  by  the  coking 
process  itself.  Another  method  makes  use  of  the  electric  current 
to  carbonize  the  peat.  Comparatively  recently,  several  processes 
by  which  artificial  coal  or  briquets  have  been  made  successfully 
from  peat  by  the  application  of  machinery  have  been  patented, 
but  have  not  yet  been  fully  established  on  an  industrial  basis. 

Carboniferous-Mud  Briquets. — Carboniferous  mud  is  a  lower 
vegetable  deposit  than  peat  or  turf.  In  some  instances,  it  is 
derived  from  the  refuse  of  the  turf  industry;  at  other  localities, 


TREATISE  ON  COKE  413 

along  the  estuaries  of  lakes  and  rivers,  these  black-mud  accumu- 
lations are  found.  They  are  composed  mainly  of  vegetable  matter, 
rotted  principally  under  water  and  mixed  with  various  percent- 
ages of  earthy  matters.  The  black  mud  requires  very  little  prep- 
aration for  its  manufacture  into  briquets;  the  most  important 
consists  in  drying  the  briquets  after  leaving  the  press.  The 
manufacture  of  fuel  on  a  large  scale  from  the  black  mud  of  grass 
meadows  is  an  important  industry  in  several  countries  of  Europe, 
notably  in  Holland  and  Russia;  mud  briquets  are  also  reported  as 
being  made  on  a  commercial  scale  in  the  United  States. 

Petroleum  Briquets. — Petroleum  briquets  have  been  manufac- 
tured in  various  ways  in  different  countries,  notably  in  Russia, 
France,  and  the  United  States,  as  a  fuel  for  steamships  and  cer- 
tain industries  where  rapid  production  of  heat  is  desirable.  The 
advantages  of  such  a  substitute  for  coal  are  readily  apparent  — 
less  storage  room,  complete  combustion,  etc.  It  is  somewhat 
surprising  that  petroleum  has  not  been  more  generally  utilized 
in  this  form.  The  objections  were  that  the  briquets  were  said  to 
injure  the  boilers  after  a  short  time,  by  reason  of  some  chemical 
action  produced  in  combustion;  further,  the  blocks  did  not  keep 
their  form  under  the  action  of  the  heat,  but  fell  through  the  fire- 
box in  a  liquid  state ;  and  the  price  is  stated  to  be  two-thirds  more 
than  that  of  coal.  A  company  is  said  to  have  been  formed  for 
the  manufacture  of  petroleum  briquets,  which  claims  to  have 
obviated  all  the  objections  except  that  in  regard  to  price.  Petro- 
leum briquets  can  be  used  for  any  kind  of  domestic  or  industrial 
work  without  changing  the  furnaces. 

Binders. — Bonding  material  is  used  to  cement  the  small  par- 
ticles of  fuel  employed  in  making  briquets  except  such  as  contain 
the  necessary  bituminous  matter,  such  as  lignite,  peat,  carbon- 
iferous mud,  and  petroleum.  The  greater  the  amount  of  bitu- 
minous matter,  the  smaller  is  the  quantity  of  binder  employed. 
The  most  common  binder  used  is  pitch  in  its  various  forms,  the 
pitch  being  a  by-product  in  gas  and  coke  making,  and  to  a  limited 
extent  from  furnace  gases  in  ironworks  that  use  raw  coal  as  a 
fuel.  Hard  pitch  is  of  foremost  importance  in  this  connection, 
and  when  of  a  good  quality  should  contain  75  to  80  per  cent,  of 
carbon  and  only  .25  to  .5  per  cent,  of  ash.  The  addition  of  from 
5  to  10  per  cent,  of  pitch  as  a  binder  improves  the  heating  value 
of  fuel  from  2  to  4  per  cent.,  depending  on  the  number  of  heat 
units  possessed  by  the  raw  material.  Tar  and  soft -pitch  binders 
have  many  disadvantages  that  do  not  apply,  to  the  same  extent, 
to  hard  pitch.  The  presence  of  the  light  and  heavy  volatile 
hydrocarbons  in  the  former  creates  smoke  and  smell  when  this 
binder  is  used  in  briquets;  also,  the  point  of  distillation  of  soft 
pitch  is  about  400°  F.,  while  that  of  hard  pitch  approximates 


414  TREATISE  ON  COKE 

800°  F.  Thus  briquets  made  with  soft  pitch  have  to  be  kept  cool 
or  they  will  soften  and,  by  sticking  together,  form  large  lumps. 
It  has  been  stated  that  the  briqueting  of  slack  and  fine  coal  in 
Germany  is  practically  limited  by  the  amount  of  pitch  obtainable 
from  the  by-product  coke  ovens. 

Among  the  other  organic  binders,  the  most  important  are 
starch  paste  and  sugar  molasses;  but  these,  and  a  few  others  of 
this  class,  have  not  as  yet  attained  more  than  local  importance. 

The  use  of  inorganic  binders  is  to  be  avoided  wherever  organic 
binders  may  be  had  at  reasonable  cost.  The  most  important 
inorganic  binder  is  magnesia  cement,  which  is  both  cheap  and 
abundant.  The  use  of  5  per  cent,  of  this  material  is  said  to  pro- 
duce a  stronger  briquet  than  that  made  by  any  other  binder; 
when  5  per  cent,  of  this  binder  is  used,  the  quantity  of  ash  added 
amounts  to  but  2.5  per  cent.  Mr.  Schorr  says  "the  process  of 


FIG.  2.     OPEN-MOLD  PRESS 

using  magnesia  cement  is  very  cheap,  as  no  drying  is  required  and 
the  only  fuel  expended  is  that  for  power.  The  briquets  harden 
gradually  at  the  ordinary  temperature,  and  after  from  6  to  10 
hours  are  strong  enough  to  be  stored  or  handled ;  in  a  few  days 
they  are  capable  of  standing  a  pressure  of  from  7,000  to  22,000 
pounds  per  square  inch.  Wherever  good  hard-pitch  briquets  are 
in  the  market,  it  will  be  difficult  for  a  magnesia-cement  briquet  to 
compete  with  it  on  account  of  the  higher  ash  content  of  the  latter. 
One  hears  and  reads  from  time  to  time  of  a  new  matrix  or 
binder  that  will  cheapen  the  cost  of  coal  briquets,  facilitate  their 
manufacture,  and  improve  their  quality;  but  these  accounts  usually 
are  founded  rather  on  the  claims  of  inventors  and  promoters  than 
on  demonstrated  industrial  results. 

Presses. — To  obtain  a  solid  briquet,  it  should  be  of  uniform 
density,  which  can  only  be  effected  by  using  a  high  pressure  and 
by  keeping  a  proper  ratio  of  the  cross-sectional  area  of  the  briquet 


TREATISE  ON  COKE  415 

to  its  height.  If  the  pressing  is  done  against  a  solid  resistance, 
and  from  one  side  only,  a  comparatively  higher  pressure  must 
be  exerted,  and  even  then  the  density  in  various  layers  will 
differ.  The  larger  the  briquet,  the  higher  should  be  the  pres- 
sure per  square  inch.  The  depth  of  the  briquet  has  an  impor- 
tant bearing  on  the  character  of  the  briquet  produced;  even 
the  largest  and  heaviest  fuel  blocks  should  not  exceed  5  inches 
in  depth. 

There  are  two  general  types  of  presses  in  use :  the  press  with 
open  mold  and  the  press  with  closed  mold.  The  open-mold  press, 
Fig.  2,  is  extensively  used  for  lignite  and  peat;  it  works  well  with 
washed  coals  containing  up  to  20  per  cent,  of  water  and  gives  a 


FIG.  3.     CLOSED-MOLD  PRESS 

big  production.  Its  construction  is  simple  and  solid,  and  it  is 
easy  to  work.  It  has  for  its  elements  a  pipe  or  tube  whose  cross- 
section  is,  in  shape  and  size,  that  of  the  face  of  the  briquet,  and 
a  piston  that  fits  one  end  of  the  pipe  or  mold,  the  other  end  being 
open.  When  a  sufficient  amount  of  "paste,"  or  briqueting  mate- 
rial, falls  into  the  mold,  the  piston  moves  forward  and  forms  a 
briquet;  when  the  piston  recedes,  new  material  drops  from  a  hopper 
into  the  space  between  the  piston  and  the  previous  briquet  pressed; 
then  the  piston  moves  forward  again,  pressing  a  new  briquet  and 
at  the  same  time  forcing  a  finished  briquet  from  the  open  end  of 
the  mold,  thus  forming  a  continuously  moving  column.  The  pres- 
sure exerted  by  the  piston  in  this  type  of  press  need  not  be  -very 
great,  being  dependent  on  the  friction  of  the  completed  briquets 


416 


TREATISE  ON  COKE 


against  the  walls  of  the  mold  and  the  length  of  the  mold.  To 
increase  the  pressure,  the  mold  is  sometimes  tapered  from  the 
piston  to  the  open  end.  Notwithstanding  the  difficulty  of  secur- 
ing a  desirable  pressure  in  this  type  of  mold,  it  is  the  one  most 
in  use,  having  the  counterbalancing  advantage  of  rapid  pro- 
duction of  briquets,  which  the  closed-mold  method  lacks.  It  is 
very  wasteful  in  the  consumption  of  power.  Open-mold  machines 
are  generally  fitted  up  in  pairs  on  the  Bourriez  continual-motion 
system. 

The  closed-mold,  or  solid-resistance,  presses,  Figs.  3  and  4,  are 
divided  into  two  classes;  tangential  presses  and  plunger  presses. 
The  tangential  type  comprises  a  mechanism  that  consists  of 
wheels  working  against  each  other,  and  carrying  molds,  or  molds 


FIG.  4.     PLAN  OF  CLOSED-MOLD  PRESS 

and  corresponding  teeth,  on  their  peripheries.  The  action  of  this 
press  is  continuous  and  permits  a  large  number  of  small  briquets 
to  be  made  in  a  short  time.  However,  the  briquets  are  apt  to  be 
poorly  and  unevenly  pressed,  and  the  waste  of  material  and  the 
wear  upon  the  machine  is  very  high,  while  from-9  to  10  per  cent, 
of  binder  is  required.  This  press  makes  the  familiar  egg-shaped 
briquets  suitable  for  domestic  use,  but  generally  too  expensive  for 
industrial  purposes. 

The  more  important  class  of  the  closed-mold  type  is  the  plunger 
press.  In  this  machine,  molds  filled  with  the  paste,  or  briquet- 
ing  material,  by  a  distributor,  pass  under  an  arrangement  that 
exerts  pressure  on  one  or  both  sides  of  the  briquet,  which  is  after- 
wards ejected  automatically.  A  large  number  of  these  presses  are 
in  operation  making  briquets  of  all  sizes. 


TREATISE  ON  COKE  417 

METHODS  AND  COSTS  OF  MANUFACTURING  BRIQUETS 

Having  considered  the  general  character  and  the  various  kinds 
of  briquets,  we  will  now  take  up  the  methods  and  costs  of  manu- 
facturing briquets  in  the  principal  countries  manufacturing  this 
form  of  fuel.  Much  of  the  information  relative  to  the  briquet 
industry  on  the  continent  of  Europe  and  in  England  is  taken 
from  the  reports  of  the  United  States  Consuls  stationed  in  these 
countries. 

Briqueting  in  Austria-Hungary. — While  the  manufacture  of  the 
briqueted  fuel  in  Austria-Hungary  is  of  comparatively  recent 
origin,  it  has  had  so  rapid  a  growth  that  it  bids  fair  soon  to  be 
classed  among  the  important  industries  of  the  country.  Its 
remarkable  development  is  attributed  to  two  causes,  viz.,  the 
comparatively  high  price  of  fuel  in  some  parts  of  the  monarchy 
and  the  great  abundance  of  waste  or  inferior  coal  in  others. 

Until  quite  recently,  briquets  have  constituted  only  a  com- 
paratively insignificant  item  in  the  household  economy  of  the 
inhabitants  of  Vienna.  During  1902,  however,  various  enter- 
prising firms,  chiefly  German,  took  energetic  steps  to  popularize 
the  article,  and  their  efforts  have,  to  a  certain  extent,  been  suc- 
cessful. Trieste  has  one  briquet  factory  that  turns  out  about 
5,000  tons  of  fuel  annually. 

The  principal  ingredient  of  the  briqueted  fuels  manufactured 
in  Austria-Hungary  is  coal  dust  or  screenings.  In  Bohemia,  coal 
is  mined  in  large  quantities,  and  briquets  are  chiefly  made  of  the 
refuse  of  the  coal.  In  the  greater  portion  of  Hungary,  bituminous 
coal  is  employed  in  the  manufacturing  plants,  while  in  Styria 
and  Bosnia,  lignite  is  utilized.  In  Croatia-Slavonia,  as  well  as  in 
Carinthia  and  some  other  parts  where  large  quantities  of  charcoal 
are  produced,  charcoal  dust  has  of  late  also  been  used  in  the  manu- 
facture of  "patent  fuel." 

The  cost  of  manufacturing  varies  greatly,  according  to  the  loca- 
tion of  the  plant  and  the  kind  of  material  used.  Bituminous 
screenings  are,  of  course,  cheaper  than  anthracite,  and  the  price  of 
crude  labor  varies  in  the  different  portions  of  the  monarchy  from 
30  cents  to  $1  and  even  more  a  day.  The  briquets  made  in  Trieste 
are  of  the  charcoal  variety  and  are  produced  at  a  cost  of  about 
$10  per  ton.  The  cost  of  manufacture  of  lignite  briquets  in  the 
province  of  Styria  is  said  not  to  exceed  $4  per  ton.  The  selling 
price  of  lignite  and  bituminous  briquets  ranges  from  $4.50  to 
$6.50  per  ton,  while  the  charcoal  briquets  manufactured  at  Trieste 
sell  at  $12  per  ton.  The  prices  of  other  fuel  for  domestic  use  are 
as  follows:  beech  wood,  $2  per  cubic  meter,  or  about  $7  per  cord; 
bituminous  coal,  from  $3  to  $6  per  ton,  according  to  quality;  gas 
coke,  $10  per  ton;  charcoal,  $12  per  ton.  Nearly  all  the  methods 
of  manufacture  are  of  German  origin,  and  Germany  still  supplies 
many  of  the  machines  used. 


418  TREATISE  ON  COKE 

The  charcoal  briquets  manufactured  in  Trieste  are  made  in 
the  following  manner:  The  charcoal  screenings  are  first  ground 
fine,  after  which  coal  tar  is  added,  and  the  mixture  stirred  until 
it  has  the  proper  consistency  for  pressing.  The  latter  is  then 
molded  into  egg-shaped  pieces  weighing,  in  a  dry  condition,  from 
2  to  3  ounces.  These  pieces  are  dried  in  kilns  and  in  the  open  air. 

Substantially  the  same  process  is  employed  in  the  manufac- 
ture of  lignite  and  bituminous  briquets.  Lignite,  however,  owing 
to  its  low  heating  power,  is  seldom  used  without  the  addition  of 
from  20  to  30  per  cent,  of  anthracite  or  bituminous  coal.  This 
mixture  of  coal  is  likewise  ground  fine,  and  about  10  per  cent,  of 


FIG.  5.     THE  WEISNER  BRIQUET  MACHINE 

pitch  added.  The  composition,  after  having  been  thoroughly 
blended  and  partially  dried  in  a  kiln  having  a  temperature  of 
from  158°  to  176°  F.,  is  pressed  into  bricks  weighing  about  10 
pounds  each.  The  product  is  then  ready  for  the  market. 

Formerly,  pitch  was  universally  used  as  a  bonding  material, 
but  its  present  high  price  has  led  many  manufacturers  to  substi- 
tute for  it  a  composition  of  milk  of  lime,  tar,  and  "Weisner's 
patent  bonding  material"  (a  solution  of  sulphuret  of  lime  with  free 
sulphurous  acid,  resinous  substances,  and  lignite). 

The  average  daily  capacity  of  the  Trieste  plant,  which  employs 
from  twenty  to  thirty  men,  is  from  20  to  30  tons. 

Edward  Weisner  and  brother,  of  Vienna,  manufacture  a  hand- 
power  machine,  Fig.  5.  It  works  as  follows:  The  funnel  or 
hopper  a  is  filled  with  the  composition  to  be  pressed  into  briquets. 


TREATISE  ON  COKE 


419 


A  turn  of  the  flywheel  causes  the  plunger  b  to  rise.  The  sliding 
apparatus  c,  which  in  the  meantime  has  been  filled  from  the  hop- 
per, then  passes  over  the  mold  and  pours  its  contents  into  it. 
Another  turn  of  the  wheel  brings  the  sliding  apparatus  back  under 
the  funnel  to  be  again  filled.  In  the  meantime  the  plunger  enters 
into  the  mold  and  sufficiently  compresses  the  contents  to  form 
the  briquet.  The  plunger  and  the  bottom  of  the  mold  then  rise 
simultaneously  until  the  latter  is  in  line  with  the  base  of  the 
sliding  apparatus  and  the  pallet  placed  on  the  discharging  table  d. 
While  the  plunger  continues  to  rise,  the  sliding  apparatus,  filled 
with  material,  moves  over  the  mold,  thereby  pushing  the  finished 
briquet  on  the  pallet  and  at  the  same  time  discharging  its  contents 
into  the  mold,  whose  moving  bottom  has  in  the  meantime  again 
dropped  down. 

The  heating  value  of  the  various  kinds  of  coal  briquets  manu- 
factured in  Austria  is  stated  to  be  as  given  in  the  following  table: 


Kind 

Calories 

Anthracite  
Bituminous  
Lignite   
Charcoal  

5,000  to  6,000 
3,500  to  4,000 
3,000 
7,000  to  8,000 

Briqueting  in  Belgium.— The  latest  available  official  statistics 
concerning  briqueted  fuel  in  Belgium  cover  the  year  1901.  They 
show  that  there  were  at  that  time  thirty  plants  engaged  in  the 
manufacture  of  various  kinds  of  briquets,  -  distributed  as  follows: 
Twenty-seven  plants  in  the  province  of  Hainaut,  with  a  total  of 
sixty  presses  and  employing  1,237  workmen,  and  three  plants  in 
the  province  of  Namur,  with  ten  presses  and  employing  83 
workmen. 

The  amount  of  coal  consumed  in  the  province  of  Hainaut  was 
1,130,460  tons,  from  which  was  produced  1,236,450  tons  of  briquets, 
valued  at  $4,608,068,  or  $3.726  (19.31  francs  per  ton).  The  fol- 
lowing tabulated  statement  shows  the  annual  production  and  the 
average  price  per  ton  of  briquets  in  the  province  of  Hainaut  dur- 
ing the  last  5  years. 


Year 

Production 
Tons 

Average  Price 
Per  Ton 

1897 

1,030,330 

$2.413 

1898 

1,119,180 

2.586 

1899 

1,023,290 

3.128 

1900 

1,091,150 

4.599 

1901 

1,236,450 

3.726 

420 


TREATISE  ON  COKE 


The  three  plants  in  the  province  of  Namur  make  coal  and  pitch 
briquets,  and  during  the  year  1901  consumed  94,790  tons  of  coal 
in  the  production  of  105,870  tons  of  briquets,  valued  at  $383,915.25 
or  $3.626  per  ton. 

Materials  from  which  briquets  are  made  in  Belgium  vary  accord- 
ing to  the  use  for  which  the  fuel  is  destined.  When  manufactured 


(fe)  PLAN 
FIG.  6.     MACHINE  FOR  SORTING,  WASHING,  AND  MAKING  BRIQUETED  FUEL 

a,  separating  drum;  b,  endless-chain  bucket;  c,  oscillating  table:  d,  coal-washing  tubs; 
e,  tank  (or  absorbing  well);  /.  bucket  chains;  g,  drain  pipes;  h,  forcing  screw;  i,  bucket  chain; 
/,  recipient;  k,  proportional  distributor  of  pitch  and  coal;  /,  bucket  chain;  m,  Carr  grinder; 
n,  bucket  .chain;  o,  pug  mill  and  distributor;  p,  r,  distributors;  q,  s,  briquet  presses; 
/,  cutting  table;  «,  steam  heater;  v,  steam  engine;  w,  ventilator;  x,  beams  and  columns; 
y,  general  transmission. 

for  railroad  consumption,  generators,  power  plants,  etc.,  about 
90  per  cent,  of  bituminous  coal  is  used,  to  which  is  added  mineral 
pitch  or  coal  tar.  The  mixture  varies  according  to  the  nature  af 
the  coal  employed,  whether  ruddy,  close,  or  half  free-burning 


TREATISE  ON  COKE  421 

coal.  The  paste  contains  from  13  to  14  per  cent,  of  water.  When 
intended  for  domestic  use,  about  30  per  cent,  of  clay  or  marl  is 
added.  Briquets  of  an  inferior  quality  are  made  from  a  mixture 
of  sawdust,  tannery  and  brewery  residue,  peat,  turf,  and  lignite. 

A  plant  for  separating,  washing,  and  making  coal  briquets  is 
illustrated  in  Fig.  6.  This  plant  can  work  up  500  tons  of  coal  into 
briquets  in  10  hours,  and  costs  8,000  francs  ($1,544).  The  work 
is  divided  as  follows:  (1)  to  sort  300  tons  of  coal;  (2)  to  wash 
150  tons;  (3)  to  make  120  to  150  tons  of  briquets  weighing  11 
pounds  each,  and  50  tons  of  ovoid  balls  weighing  5.289  ounces  each. 

The  coal  first  passes  through  the  separating  drum  a,  which 
separates  it  into  three  classes,  70-40  millimeters,  40-25  milli- 
meters, and  25-0  millimeters.  The  70-40  and  40-25  sizes  are  put 
aside  for  sale.  The  25-0  size  is  passed  into  the  tank  by  means 
of  the  endless-chain  buckets  6,  from  which  it  passes  into  the  shaking 
screen  c,  which  separates  it  again  into  three  classes.  The  first 
two  classes  are  carried  to  the  washing  tank  d\  after  washing,  they 
are  carried  to  tank  e,  by  the  endless-chain  buckets  /,  which  then 
hoists  them  to  the  draining  tower  g.  The  third  class  is  also  ele- 
vated by  a  movable  bucket  to  a  storing  tower.  A  screen  conveyer  h, 
working  at  the  foot  of  the  towers,  removes  the  washed  coal,  when 
sufficiently  drained,  from  either  tower  and  permits  the  reclassing 
of  the  three  kinds  of  coal.  It  is  evident  that  the  arrangement 
permits  the  manufacture,  according  to  the  requirements  of  the 
purchaser,  of  three  sorts,  unwashed,  mixed,  or  thoroughly  washed. 
The  coal  is  then  carried  into  the  tank  of  the  endless-chain  buckets  i 
that  hoist  it  into  the  tank.  Under  this  tank  is  the  proportional 
distributor  of  pitch  and  coal  k  in  which  the  exact  division  of  pitch 
and  coal  is  made.  The  mixture  is  then  carried  to  the  Carr  pug 
mill  m  by  an  endless-chain  bucket  /.  The  Carr  pug  mill  is  con- 
sidered to  be  a  perfect  mixing  machine  and  at  the  same  time  an 
excellent  grinding  machine.  An  endless-chain  bucket  n  then 
hoists  the  material  to  the  mixing  machine  o,  where  it  is  trans- 
formed, by  the  action  ot  steam,  into  a  cohesive  paste,  which  runs 
through  two  openings  placed  on  the  right  and  left  side  of  the  -pug 
mill.  Two  screw  conveyers  specially  disposed  for  cooling  the 
paste-  take  it  to  distributor  p  of  the  press  q  on  one  side  and  to 
distributor  r  of  the  briquet  press  5  on  the  other.  The  briquets, 
as  they  issue  from  the  molds,  are  taken  to  the  cutting  table  /  by 
means  of  two  irons  and  separated  by  hand  and  then  are  stored 
or  delivered. 

The  average  capacity,  per  day,  of  plants  depends  entirely  on 
the  number  of  machines  in  use.  In  some  plants,  not  more  than 
6,500  briquets  are  made  per  day  of  10  hours;  while  in  more  elab- 
orately equipped  establishments,  30,000  briquets  are  turned  out 
in  the  same  number  of  hours. 

The  following  table  shows  hands  required  and  wages  paid  per 
day  to  work  an  ordinary  briquet  machine: 


422 


TREATISE  ON  COKE 


For  Labor,  Materials,  Etc. 

Cost 

One  foreman  operating  machine  
One  stoker  
One  overseer  
Two  mixers,  each  3.50  francs  

$    .965 
.868 
.772 
1  .  351 

Two  carriers,  each  3.50  francs  

1.351 

Three  boys  for  loading  briquets  on  wagons  or  cars,  each  2  francs.  . 
One  boy  for  washing  and  crushing  resin 

1.158 
386 

Total 

6  851 

Oils,  packings,  etc  
Fuel    900  kilos  at  20  francs  per  ton  

1.061 
3  .  474 

Total                                                        

4  535 

Washed  coal  dust   25  3  tons  at  8  12  francs 

39  647 

Pitch  resin  (7  per  cent  )    1  957  kilos  at  75  75  francs  . 

28  596 

Tar  (25  per  cent.),  699  kilos  at  60  francs  
Total 

8.096 
76  339 

Grand  total  

87.725 

Plants  are  usually  equipped  as  -follows:  steam  generators; 
one  motor  machine;  one  coal  crusher  (in  some  cases  useless)  or 
drier;  one  resin  crusher  or  boiler  for  melting  resin;  resin  and  coal 
measure  for  measuring  mixture;  heating  and  mixing  machine; 
mixing  machine;  occasionally  an  endless  cloth  for  cooling,  trans- 
porting, and  loading  the  briquets. 

The  estimated  cost  of  manufacture,  including  raw  material, 
labor,  and  interest  on  money  invested,  is  about  $3.281  (17  francs) 
per  ton,  divided  as  follows:  coal,  $1.64;  tar,  pitch,  or  resin,  $1.25; 
labor  and  interest  on  money  invested  in  plant,  $.386.  The  average 
selling  price  for  good  quality,  briquets  varies,  according  to  con- 
ditions of  contract  and  destination,  from  $3.474  (18  francs)  to 
$3.86  (20  francs)  per  ton. 

Briqueting  in  France. — Fuel  briquets  have  been  used  in  France 
for  the  past  50  years,  and  the  briquet  has  acquired  an  importance 
in  French  markets  from  which  it  is  unlikely  to  be  dislodged  so 
long  as  coal  retains  its  supremacy  as  a  generator  of  steam.  The 
product  of  the  French  mines  is  friable  and  inferior  to  the  high- 
grade  British  and  American  fuels,  and  until  the  briquet  was  per- 
fected, a  large  percentage  of  the  output  of  the  mines  represented 
a  total  loss.  The  manufactured  fuel  permits  what  was  once  largely 
refuse  to  be  sold  at  prices  running  fairly  even  with  the  prices  of 
the  choicest  coal  taken  out  of  the  domestic  mines.  The  French 
government  requires  the  railways  of  the  country  to  maintain  a 
stock  equal  to  their  requirements  for  3  months,  and  this  reserve 
usually  consists  of  briquets.  On  railroad  locomotives  and  in 


TREATISE  ON  COKE  423 

marine  service,  briquets  are  preferred  to  coal,  as  their  heat  is 
more  reliable,  which  enables  closer  calculations  to  be  made  as  to 
the  amount  of  steam  that  can  be  obtained  from  a  given  weight 
of  fuel. 

While  the  briquet  is  destined  to  continue  an  important  factor 
in  the  French  coal  trade,  the  cost  of  manufacture  is  so  great  that 
of  recent  years  every  endeavor  has  been  made  by  the  railway 
companies  and  the  manufacturers  of  boilers  to  devise  some  method 
of  burning  the  low-grade  fuel  direct,  and  with  a  considerable 
degree  of  success.  The  Belgian  railway  companies  were  the  first 
to  adopt  a  definite  scheme  and,  as  far  back  as  1395,  began  to 
make  use  of  coal  dust,  which  did  not  cost  over  $1.15  (6  francs)  per 
ton.  In  France,  The  Company  of  the  East  first  took  up  the  mat- 
ter and  is  now  burning  washed  small  coal  which  is  very  pure,  but 
which,  nevertheless,  may  be  bought  at  a  far  lower  price  than 
run-of-mine  coal  or  briqueted  fuel.  The  Paris,  Lyons,  and  Medi- 
terranean Railway  Company,  which  has  for  years  burned  briqueted 
fuel  exclusively,  and  owns  three  large  factories  for  the  treatment 
of  the  small  coal  mined  along  its  system,  has  followed  suit  with 
considerable  success.  In  the  burning  of  fine  coal  direct,  the 
fireman  is  obliged  to  exercise  much  greater  care,  and  the 
grate  bars  must  be  closer  together.  Without  changing  the  fire- 
box and  by  using  a  combination  fuel,  the  Paris,  Lyons,  and 
Mediterranean  Company  has  succeeded  in  securing  the  same 
power  per  hour  and  per  square  yard  of  grate  surface  as  was 
formerly  obtained  with  high-grade  fuel  alone.  In  accomplishing 
this  result,  both  of  the  French  companies  employ  coal  of  rich 
quality  that  tends  to  conglomerate  in  the  fire.  These  methods 
have  been  adopted  by  the  Paris,  Lyons,  and  Mediterranean 
Railway  for  the  movement  of  freight,  but  not  yet  for  the 
movement  of  fast  passenger  trains. 

For  general  industrial  purposes,  two  systems  of  burning 
extremely  fine  coal  are  now  recognized  as  practicable.  One  of 
these  involves  the  feeding  of  the  coal  from  a  hopper  upon  a  moving 
grate.  The  second  system  requires  the  construction  within  the 
furnace,  of  a  series  of  narrow  shelves  on  which  the  coal  rests,  the 
grate  bars  being  erected  vertically.  These  great  economies  are 
not  possible  upon  shipboard,  and,  granting  their  complete  success; 
still  leave  the  briquet  supreme  as  a  means  of  making  the  French 
fine  coal  available  for  navigation  and  for  general  domestic  pur- 
poses. Being  dearer  than  coal,  briquets  are,  according  to  one 
authority,  seldom  used  in  manufacturing  establishments.  The 
amount  of  briqueted  fuel  consumed  in  France  in  1902  was  prob- 
ably over  2,000,000  tons,  and  its  use  is  increasing. 

The  principal  binder  used  is  pitch.  The  price  of  this  pitch, 
most  of  which  is  imported  from  Great  Britain,  rises  and  falls  in 
sympathy  with  that  of  coal.  The  highest  quoted  price  since  1873 
was  $11.58  per  ton  in  1900,  and  it  was  as  low  as  $1.79  in  1888. 


424  TREATISE  ON  COKE 

All  qualities  of  coal  are  susceptible  of  being  conglomerated; 
but  in  France,  the  half-bituminous  quality  of  fuel,  of  from  13  to 
17  per  cent,  volatile  matter,  is  particularly  employed.  The  fine 
coal  of  this  grade  coheres  with  difficulty  when  employed  directly 
and  becomes  much  more  valuable  when  manufactured.  Certain 
coals  in  the  Franco-Belgian  basin,  containing  not  more  than  12 
to  14  per  cent,  of  volatile  matter,  also  make  good  briquets  if 
employed  with  from  9  to  10  per  cent,  of  dry  pitch.  When  the 
quality  of  the  coal  is  so  low  as  to  contain  not  more  than  10  per 
cent,  of  volatile  matter,  the  resulting  briquets  burn  slowly  and 
with  difficulty.  The  lignites  are  slow  to  conglomerate  alone,  but 
mixed  with  other  combustibles  yield  a  good  product.  At  the 
factory  near  Marseilles,  the  half -rich  anthracite  of  the  Depart- 
ment of  Gard,  and  Fuvean  lignite  are  used. 

While  briquets  are  sold  in  a  very  large  number  of  forms,  the 
three  notable  types  are:  (1)  the  large  square  or  cylindrical 
briquet,  weighing  about  20  pounds  each;  (2)  the  perforated 
rectangular  briquet,  weighing  about  1J  pounds,  and  sold  for  gen- 
eral domestic  and  industrial  purposes;  (3)  the  round  or  egg- 
shaped  briquet  for  domestic  purposes.  The  standard  recognized 
for  these  briquets  by  the  French  Admiralty  is  the  Anzin  briquet, 
a  briquet  yielding  from  8,200  to  8,500  calories.  The  manufac- 
tured fuel  for  the  navy  is  required  to  reach  this  standard,  and 
the  railway  service  is  scarcely  less  exacting.  The  briquet  for 
ordinary  purposes,  being  in  the  majority  of  cases  manufactured 
from  coal  of  the  poorest  and  smallest  grade,  averages  not  more 
than  6,600  calories.  These  commercial  briquets  are  in  large  part 
manufactured  from  lignite  (which  is  used  with  difficulty  alone) 
in  combination  with  forge  coal  and  a  relatively  high  percentage 
of  pitch.  Because  of  these  requirements,  it  is  almost  invariably 
necessary  to  wash  the  small  coal,  at  considerable  expense,  before 
the  manufacture  of  briquets  begins. 

The  manufacture  of  briquets  in  France  includes  coal-crushing, 
washing,  and  drying  processes,  the  first  two  processes  of  which 
are  entirely  familiar.  Generally  the  coal  delivered  to  the  pressing 
machines  is  damp ;  and  when  the  moisture  exceeds  4  to  5  per 
cent,  it  is  necessary  to  remove  the  excess.  The  presses  that  apply 
a  pressure  lasting  relatively  for  a  considerable  time,  such  as  the 
kivollier,  Evrard,  and  Bourriez,  relieve  the  paste  of  the  excess 
water  and  give  good  results  even  though  the  paste  as  it  enters 
contains  as  much  as  10  per  cent,  of  water.  The  Rivollier,  how- 
ever, is  the  only  machine  that  absolutely  guarantees  this  result. 
The  presses  operating  instantaneously,  like  the  Bietrix,  which  is 
manufactured  by  the  house  of  Couffinhal  et  Ses  Fils,  at  St.  Etienne 
(Loire),  France,  give  excellent  results,  but  the  product  requires 
careful  drying.  It  is  recognized  as  necessary  and  useful  to  leave 
1^  to  3  per  cent,  of  water  in  the  paste  when  ready  for  the  press. 
This  quantity  contributes  to  the  plasticity  of  the  mass  during  the 


TREATISE  ON  COKE 


425 


application  of  the  pressure.  In  no  event  does  the  density  of  the 
briquet  equal  that  of  solid  coal.  There  remain  always  certain 
spaces  between  the  component  particles,  and  if  the  paste  is  too  dry 
these  spaces  contain  compressed  air,  which  diminishes 'the  solidity 
of  the  mass. 

In  some  cases,  it  is  necessary  to  eliminate  nearly  all  the  water 
possible  from  the  coal  before  the  material  passes  to  the  presses; 
consequently,  a  drying  operation  is  required,  such  as  is  carried  on 


FIG.  7.     OVEN  WITH  REVOLVING  TABLE 

in  the  oven  shown  in  Fig.  7.  This  oven  is  circular  in  shape,  com- 
posed of  a  revolving  platform  of  cast  iron,  and  works  continuously 
with  the  agglomerating  machine.  The  platform  is  surrounded  by 
masonry  covered  with  sheet  iron,  on  which  rests  a  dome  with  a 
passage  in  the  center  for  a  cylinder  of  cast  iron  with  a  shaft  fur- 
nished with  flukes.  A  lateral  firebox  produces  the  temperature 
necessary  to  the  heating  of  the  coal  and  the  elimination  of  any 
excess  of  water.  The  flames,  after  passing  over  the  upper  surface 
of  the  coal,  heat  the  dome,  pass  under  the  revolving  table,  and 


426 


TREATISE  ON  COKE 


TREATISE  ON  COKE 


427 


escape  at  the  opposite  end  by  a  chimney.  Around  the  covering 
of  the  oven  are  arranged  six  openings.  The  first  four  are  used 
to  introduce  arms  provided  with  spikes  that  turn  the  material, 
presenting  all  its  parts  to  the  heat  of  the  flame.  Opposite  the 
fifth  aperture  are  two  bars  that  gradually  bring  the  material  from 
the  center  to  the  circumference.  These  bars  also  regulate  the 


FIG.  9.     BIETRIX  BRIQUET  PRESS 

thickness  of  the  layer  of  coal.  By  means  of  scrapers,  the  coal 
that  is  sufficiently  dried  is  removed  from  the  table,  through  the 
sixth  opening,  to  a  conveyer  that  carries  it  to  the  press,  where  it 
is  made  into  briquets.  Fig.  8  shows  the  method  of  operating 
such  a  drying  oven  in  connection  with  a  press. 

The  pitch  for  the  binder  should  be  crushed  as  fine  as  possible 
and  preferably   should  be   melted  before  being  mixed  with  the 


428 


TREATISE  ON  COKE 


coal  and  brought  to  the  temperature  chosen  for  the  fusion.     It  is 
melted  in  huge  basins  with  bottoms  slightly  inclined  toward  the 

point  of  discharge,  the  load 
usually  being  7  tons.  Fre- 
quently the  pulverized  pitch  is 
mixed  dry  with  the  coal,  and 
the  mixture  is  then  brought 
to  the  proper  temperature. 

The  mixing  mill  consists 
of  a  vertical  cylinder  within 
which  the  shaft  operates 
swiftly  moving  paddles  upon 
the  churn  principle,  by  which 
the  incoming  pitch  and  coal 
are  beaten  and  mixed  as  they 
move  downwards  toward  the 
point  of  discharge.  This  cyl- 


inder is  heated  by  steam,  and 
requires  as  much  as  110 
pounds  of  steam  per  ton. 

In  1903,  the  British  presses 
were  extensively  used,  though 
the  Bietrix  machine  proba- 
bly stands  equally  high.  This 
latter  machine  presses  the 
briquet  simultaneously  on  its 
two  faces  upon  the  principle 
of  a  nut  cracker,  the  various 
models  producing  18,  50,  90, 
and  150  tons  in  12  hours. 
The  weight  of  the  briquets 
is  usually  13.2  pounds,  but 
may  be  increased  to  25  pounds. 
Its  successful  operation  re- 
quires a  paste  containing  1|  to 
3  per  cent,  of  water  and  6  to 
9  per  cent,  of  pitch,  and  the 
pressure  varies  from  1,300  to 
2,300  pounds  per  square  inch. 
The  Bietrix  press  is  shown 
in  perspective  in  Fig.  9,  in 
plan  in  Fig.  10  (a),  and  eleva- 
tion in  Fig.  10  (b). 

The  double  compression 
is  effected  by  pistons  a  and  6, 
Fig.  10,  attached  to  upper 

beam  c  and   lower  beam  d,   respectively,   working  in   molds  on 
the  revolvable  disk  e      The  beams  c  receive  their  motion  through 


TREATISE  ON  COKE  429 

rods  connecting  them  with  cranks  /.  The  operation  of  forming 
the  briquet  is  as  follows:  The  material  in  the  mold  is  pressed 
down  by  the  descending  upper  piston  a  until  the  upper  layer 
of  the  briquet  produces  so  strong  friction  on  the  walls  of  the  mold 
that  it  will  not  yield  any  longer;  at  this  stage  the  pivot  g  of  the 
beam  c  shifts,  the  lower  beam  d  is  brought  into  action,  and  pis- 
ton h  then  compresses  the  lower  part  of  the  briquet  in  such  a 
way  that  the  pressure  on  both  parts  is  equal.  The  hydraulic 
cylinder  i  is  so  connected  to  the  beams  as  to  regulate  the  pressure 
on  the  briquet  and  it  also  acts  as  a  safety  apparatus.  After  the 
briquet  is  formed  and  the  pistons  a,  h,  and  b  have  been  removed 
from  the  molds,  the  mold  disk  e  is  turned  by  pins  on  its  under 
side  engaging  a  cam  k  on  the  crank-shaft.  When  the  briquet  in 


FIG.  11.     THE  DUPUY  BRIQUET  PRESS 

the  mold  comes  under  the  piston  6,  it  is  ejected  and,  falling  upon 
a  conveyer,  is  loaded  into  a  car. 

Another  excellent  press,  Fig.  11,  is  that  of  Th.  Dupuy  &  Fils, 
Paris.  This  company  guarantees  to  supply  a  plant,  producing 
100  tons  of  briquets  per  day,  briquets  weighing  13.2  pounds 
each,  for  $14,275,  external  shed  included.  The  builders  calcu- 
late 2  horsepower  per  ton  of  briquets  produced  per  hour,  to 
which  must  be  added  2  horsepower  per  ton  for  the  several  neces- 
sary operations. 

The  presses  for  the  manufacture  of  balls  and  egg-shaped  fuel, 
Fig.  12,  operate  on  a  different  principle  from  the  others.  While 
the  briquets  are  sometimes  piled  directly  into  railroad  cars,  the 
rule  seems  to  be  to  discharge  them  from  the  press  upon  a  long 
conveyer,  which  permits  them  to  cool  and  prevents  a  high  per- 
centage of  breakage,  which  is  certain  to  result  if  they  are  handled 
while  still  warm. 


430  TREATISE  ON  COKE 

In  1882,  the  gas  company  at  Lyons  began  the  manufacture  of 
briquets  from  coke,  employing  the  Dupuy  machine.  The  coke 
dust  is  mixed  without  further  crushing  with  pitch  and  tar.  The 
impurity  of  coke  dust  requires  that  it  shall  be  washed  and  results 
in  a  loss  of  weight  of  20  per  cent.  The  washing  process  costs 
29  cents  per  ton  of  weight  before  the  washing,  and  the  dust  itself 
being  quoted  at  96  cents,  the  washed  product  costs  $1.56  per  ton. 
The  complete  installation  of  this  plant  cost  the  company  about 
$8,685,  not  including  the  building.  The  production  per  day  of 

10  hours  is  6,500  briquets,  the  gross  weight  being  28  tons.     For 
this  production  there  are  required  one  foreman,  one  fireman,  three 
laborers,  four  boys,  costing  $6.84.     The  general  expenses  per  day 
amount  to  $4.52.     The  raw  material  cost  is  divided  as  follows: 
washed  dust,  25.3  tons,  $39.66;  pitch,  4,305  pounds,  $28.60;  tar, 

1,538  pounds,  $8.10;  total,  $76.36. 
Adding  thereto  the  cost  of  labor 
and  the  general  expenses,  the  total 
daily  expenses  amount  to  $87.72. 
This  makes  the  cost  of  the  product 
$3.14  per  ton.  The  market  price 
of  briquets  follows  the  price  of  coal, 
the  former  being  about  5  francs 
(96£  cents)  per  ton  higher  than 
the  latter. 

There  is  a  wide  difference  in  the 
cost  of  manufacturing  the  briquets, 
attributable  not  only  to  the  obsolete 
machinery  employed  in  many  cases, 
but  to  the  conditions  under  which 
the  coal  is  produced.  The  cost 

FIG.  12.     PRESS  FOR  MAKING  EGG-         j  .\  .  . 

SHAPED  BRIQUETS  depends   on  the   equipment   of  the 

mill   and   the   rate   of   wages   paid. 

It  may  be  stated  as  a  fair  estimate  that  six  workmen  can  turn 
out  100  tons  per  day.  The  equipment  of  such  a  plant  costs  about 
$20,000.  The  labor  cost  runs  from  11  to  30  cents  per  ton,  inclu- 
ding the  discharging  of  the  coal  and  the  loading  of  the  briquets. 
The  wear  and  tear  of  the  machinery  is  seldom  less  than  5  cents 
per  ton,  and  occasionally  reaches  from  19  to  39  cents  per  ton. 
The  expense,  per  ton  in  detail,  of  manufacturing  the  briquets 
at  one  plant  where  two  Bietrix  presses  were  producing  250  tons 
per  day  and  working  24  hours  per  day,  is  as  follows:  superin- 
tendent, $.007;  manipulation  of  cars,  $.005;  discharge  of  pitch, 
$.009;  discharge  of  coal,  $.012;  crushing  material,  $.032;  manu- 
facture, $.041;  loading  trucks,  $.015;  miscellaneous  labor,  $.012; 
firemen  and  engineers,  $.019;  total  labor  cost,  $.152.  Supplies: 

011  and   grease,   $.017;   miscellaneous,    $.014;   wear   and   tear   on 
machinery,   $.019;  fuel,   at   6  francs  per  ton,   $.010;  total,   $.11. 
In  making  up  this  total,  labor  is  calculated  at  60  to  77  cents  per 


TREATISE  ON  COKE  431 

day.  In  another  plant,  composed  of  Rivollier  presses,  the  total 
cost  per  ton  amounts  to  42  cents.  This  plant  requires  the  services 
of  forty-one  men,  who  are  paid  at  from  60  to  65  cents  per  day. 

The  most  important  item  in  the  first  cost  of  the  coal  briquets 
is  the  pitch,  the  price  of  which  is  twice  as  much  in  the  interior  as 
at  the  seaboard.  Assuming  as  a  minimum  a  consumption  of  6  per 
cent,  of  pitch  at  a  low  price — that  is,  $5.79  per  ton — the  cost 
under  this  head  will  be  34.7  cents.  Add  to  this  the  expense  of 
labor  and  miscellaneous  materials,  estimated  at  28.9  cents,  and 
we  have  a  total  theoretical  cost  of  63.6  cents  per  ton.  However, 
the  seaboard  factories  usually  work  for  the  marine  and  employ  at 
least  8  per  cent,  of  pitch  in  order  to  secure  a  satisfactory  cohesion. 
Under  these  circumstances  the  minimum  cost  of  manufacture  and 
materials  will  reach  75.2  cents.  Mr.  De  Graffigny  furnishes  other 
figures,  which  lead  him  to  say  that  a  maximum  of  $1.698  per 
ton  for  labor  and  materials  should  never  be  exceeded  by  a  welV 
organized  plant. 

The  plant  at  Flers  (Nord)  is  considered  fairly  representative, 
and  is  quoted  for  a  production  of  220  tons  per  24  hours.  It  includes 
a  washing  apparatus  for  cleaning  the  coal,  a  double  Bourriez 
press,  Pig.  13,  a  50-horsepower  Corliss  engine,  and  various  other 
machines,  tram  lines,  warehouses,  stables,  forge,  ten  houses,  load- 
ing crane,  one  locomotive,  four  cars,  and  cost  $135,100  in  1881,  not 
including  the  land. 

Mr.  Robert  P.  Skinner,  United  States  Consul-General,  concludes 
that  the  manufacture  of  briquets  is  of  the  utmost  importance  in 
France,  where  the  native  fuel  is  poor  in  quality,  and  must  be  sub- 
jected in  large  part  to  artificial  treatment;  also,  that  the  produc- 
tion of  this  fuel  may  be  advantageously  taken  up  in  the  United 
States.  However,  he  believes  that,  as  a  rule,  a  more  direct  inter- 
est should  be  taken  in  studying  methods  of  burning  small  coal  as 
such,  by  means  of  inclined  fireboxes  and  other  devices.  He  states 
that  certainly  every  coal  company  should  utilize  its  refuse  in 
generating  its  own  operating  power  with  greater  economy  than 
by  converting  it  into  briquets.  The  industries  located  in  coal- 
mining regions  could  advantageously  adopt  the  same  methods. 
When  there  is  a  surplus  of  poor  coal  after  these  demands  are 
satisfied,  the  conversion  of  the  residue  into  briquets  may  be  under- 
taken with  assurance  that  if  the  work  is  scientifically  carried  on, 
the  product  will  sell  on  a  plane  with  large  coal  of  the  same  grade 
and  will  give  satisfaction. 

In  the  spring  of  1902,  United  States  Consul  Brunot,  of  St. 
Etienne,  reported  as  follows:  "Petroleum  briquets  have  been 
manufactured  in  various  ways  in  different  countries,  notably  in 
Russia,  France,  and  the  United  States,  as  a  fuel  for  steamships 
and  certain  industries  where  rapid  production  of  heat  is  desirable. 
A  company  has  recently  been  formed  at  St.  Etienne  for  the  manu- 
facture of  petroleum  briquets  that  claims  to  have  obviated  all 


432 


TREATISE  ON  COKE 


objections  except  that  in  regard  to  price.     The  advantages  of  the 
product  are  set  forth  as  follows: 

"The  briquet  is  composed  of  97  per  cent,  of  petroleum  and 
3  per  cent,  of  hydrocarbon.  The  volume  being  equal,  it  weighs  only, 
half  as  much  as  coal  and  gives  but  from  2  to  3  per  cent,  of  residue; 
it  produces  no  slag,  it  does  not  'run'  when  lighted,  and  keeps 
its  form  like  coal;  it  burns  without  odor  and  without  smoke;  it 


FIG.  13.     BOURRIEZ  BRIQUET  PRESS 

may  be  wetted  with  impunity,  losing  none  of  its  properties;  it 
consumes  without  explosion  or  sparks  and  yet  with  a  bright  and 
long  flame;  it  may  be  kept  indefinitely  without  deterioration. 
By  this  process,  a  degree  of  saponification  is  obtained  by  which 
the  briquets  are  rendered  unchangeable,  even  to  the  extent  that 
if  a  projectile  should  enter  a  ship's  bunker  filled  with  this  fuel 
there  would  be  no  danger  whatever  of  explosion,  the  effect  being 
the  same  as  in  the  case  of  ordinary  coal.  The  average  heating 


TREATISE  ON  COKE  433 

power  is  from  12,000  to  14,000  calories,  and  the  briquets  can  be 
employed  in  any  firebox  or  in  any  grate  for  domestic  purposes. 

"The  manufacture  of  these  briquets  is  very  simple.  They  are 
made  without  heat  and  no  danger  attends  the  operation.  The 
petroleum  is  placed  in  one  tank  and  the  chemicals  in  another, 
and  both  are  allowed  to  run  into  a  mixing  apparatus,  when  the 
chemical  combination  is  formed  immediately.  The  product  is 
then  passed  to  a  press,  where  the  desired  form  is  given.  The 
briquet  is  now  ready  for  use,  or  it  can  be  stored.  The  pressure 
used  in  molding  the  forms  is  about  300  pounds  per  square  inch. 

"As  will  be  seen,  the  mode  of  procedure  is  very  simple  and  the 
necessary  plant  inexpensive,  requiring  only  tanks,  mixer,  and  press, 
with  small  motor  power  for  the  latter  two.  Works  erected  at  a 
cost  of,  say,  $20,000  would  turn  out  several  hundred  tons  a  day. 

"The  use  of  this  chemical  combination  as  a  binder  and  enricher 
solves  a  difficulty  frequently  encountered  in  the  making  of  coal- 
dust  or  saw-dust  briquets. 

"The  same  company  manufactures  what  are  called  mixed 
briquets — half  coal  and  half  petroleum;  but  if  these  are  cheaper 
than  the  former,  they  present  less  advantages,  from  the  fact 
that  the  density  is  greater  and  the  heating  power  is  only  9,000 
calories.  A  steamer  carrying  8,000  tons  of  coal  would  require 
3,500  tons  of  mixed  briquets  and  only  2,500  of  the  pure  petroleum 
briquets." 

Briqueting  in  Germany. — United  States  Consul-General  Frank 
H.  Mason,  of  Berlin,  Germany,  has  reported  upon  the  briqueting 
industry  in  that  country  as  follows: 

Among  the  several  branches  of  German  industry  that  deserve 
attention  by  reason  of  their^  economy,  the  recovery  or  utilization 
of  some  raw  material  that  exists  unused  in  Germany,  or  because 
they  involve  the  most  intelligent  application  of  scientific  knowledge 
to  technical  processes,  may  be  reckoned  the  manufacture  of  briquets 
from  brown  coal,  peat,  and  the  dust  and  waste  of  coal  mines. 
By  reason  of  long,  careful,  scientific  experience,  briqueting  in 
Germany  has  long  passed  the  experimental  stage  and  become  a 
standard  commercial  industry.  Briquets  form  the  principal  domes- 
tic fuel  of  Berlin  and  other  cities  and  districts  in  Germany.  They 
are  used  in  locomotives  and  other  steam  fires,  and  are  employed 
for  heating  in  various  processes  of  manufacture.  Like  most  other 
important  German  industries,  the  briquet  manufacture  is  controlled 
by  a  syndicate,  which  includes  among  its  members  thirty-one  firms 
and  companies,  and  which  regulates  the  output  and  prices  for  each 
year.  The  official  report  of  this  syndicate  for  1901  gave  the  total 
output  of  briquets  for  that  year  as  1 ,566,385  tons,  and  in  this  connec- 
tion it  is  interesting  to  note  the  distribution  of  this  output :  749,208 
tons  were  taken  by  German  railways;  124,380  tons  were  sold  to 
retailers;  497,136  tons  were  sold  to  factories  and  works  of  various 


434 


TREATISE  ON  COKE 


kinds;  and  149,089  tons  were  used  by  German  merchant  steamers 
and  the  navy,  or  exported  to  German  colonies  or  neighboring 
European  districts. 

United  States  Consul  Walter  Schumann  reported  that  during 
the  year  1900  the  production  and  home  consumption  of  briqueted 
fuel,  in  Germany,  were  as  follows: 


Production 
Long  Tons 

Home 
Consumption. 
Long  Tons 

Bituminous  briqueted  fuel 

1  970  316 

1  849  916 

Lignite  briqueted  fuel 

1  025  000 

878  910 

Consul-General  Mason  continues  as  follows:  The  following 
tabulated  statement  shows  the  production,  the  sales  of  the  syndi- 
cate, and  the  mean  price  per  ton  from  1891  to  1901,  inclusive: 


Year 

Production 
Tons 

Sales  of  Syndicate 
Tons 

Price  Per  Ton 

1891 

482,495 

202,780 

$3.02 

1892 

533,075 

516,508 

2.49 

1893 

694,025 

645,144 

2.16 

1894 

745,414  ' 

719,258 

2.10 

1895 

796,363 

780,185 

2.16 

1896 

830,985 

817,300 

2.22 

1897 

943,732 

934,221 

2.38 

1898 

1,078,113 

1,245,269 

2.43 

1899 

1,530,816 

I,485yl30 

2.34 

1900 

1,563,928 

1,519,811 

2.92 

1901 

1,566,385 

1,560,230 

3.17 

German  briquet  factories  are  divided,  in  respect  to  crude 
material  employed,  into  two  general  groups:  those  that  make 
household  briquets  from  brown  coal  (lignite)  or  carbonized  peat, 
and  those  that  produce  the  so-called  "Industrie  briquets,"  using 
as  basic  material  coal  dust  or  slack,  the  waste  of  bituminous 
coal  mines. 

Household  briquets,  as  made  in  Germany  from  brown  coal, 
peat,  and  to  a  small  extent  from  anthracite  dust,  are  used  in 
grates,  heating  stoves,  cooking  stoves,  and  ranges,  and  constitute 
the  principal  household  fuel  of  Berlin  and  other  German  cities. 
They  are  cheaper  in  Berlin,  ton  for  ton,  than  anthracite  or  good 
bituminous  coal.  The  standard  household  briquet  is  about  8 
inches  in  length  by  4  inches  in  width  and  2  inches  thick,  and  is 
retailed  and  delivered  in  Berlin  at  about  $2  per  thousand  in  sum- 
mer and  $2.50  in  winter.  They  are  made  largely  from  brown  coal 
at  factories  located  mainly  in  Silesia,  Saxony,  and  in  the  Rhine 


TREATISE  ON  COKE 


435 


provinces.  There  are  in  Germany  439  brown-coal  mines,  which, 
in  1901,  produced  44,211,902  tons  of  lignite.  Of  this  whole  number 
of  mines,  181  have  each  from  one  to  six  briquet  factories,  in  each 
of  which  from  one  to  ten  presses  are  employed.  The  whole  brown- 


FIG.  14.     ZEITZ  BRIQUET  PRESS 

coal  briquet  industry  of  Germany  includes  286  factories,  with  a 
total  of  691  presses. 

Industrial  briquets  are  used  in  Germany  for  firing  locomotives 
and  other  steam  boilers,  for  smelting  and  reverberatory  furnaces, 
and  for  many  other  kinds  of  industrial  use.  They  are  made  of 

16 


436 


TREATISE  ON  COKE 


bituminous  coal  dust,  held  together  by  a  matrix  of  mineral  pitch. 
Pitch  of  this  quality  costs  in  Germany  from  $10  to  $12  per 
metric  ton. 

Anthracite  is  so  sparingly  produced  in  Germany  that  the  use 
of  hard-coal  dust  for  briquet  purposes  is  relatively  unimportant. 
Experts  have  agreed  that,  with  a  mixture  of  from  4  to  8  per  cent, 
of  matrix,  the  manufacture  of  anthracite  briquets  that  will  bear 
transportation  by  sea  or  land  in  any  climate  presents  no  technical 
difficulty.  While  Germany  is  preeminent  in  the  scientific  utili- 
zation of  lignite  and  peat  as  material  for  prepared  fuel,  it  is  not 
apparent  that  this  technical  superiority  is  so  absolute  in  the -treat- 
ment of  coal  dust.  It  is  true  that  the  coal-briquet  manufacture 
is  fully  organized  and  developed  in  Germany,  that  there  are  several 


FIG.  15.     BRIQUET  PRESS  USED  IN  SAXONY 

German  builders  of  coal-briqueting  machinery,  who  are  masters 
of  that  branch  of  construction,  but  the  same  is  true  of  France 
and  Belgium. 

Lignite  varies  in  its  value  or  adaptability  for  briqueting  pur- 
poses according  to  its  geologic  age,  hardness,  and  the  percentage 
of  water  contained.  It  is  for  this  reason  that  Austria-Hungary, 
which  has  comparatively  a  very  old  and  hard  brown  coal  that 
contains  from  26  to  28  per  cent,  of  moisture,  has  practically  no 
supply  of  briquets  from  that  source.  The  German  lignite,  on  the 
other  hand,  is  of  much  more  recent  formation;  it  contains  from 
46  to  52  per  cent,  of  water,  and  is  usually  so  soft  that  it  can  be 
cut  with  a  spade.  The  ideal  proportion  is  about  45  per  cent,  of 
water,  so  that  German  lignite  contains  rather  too  much,  while 
Austrian  contains  most  too  little,  though  this  latter  difficulty  has 
been  practically  overcome  by  steaming. 


TREATISE  ON  COKE 


437 


Fig.  14  shows  a  Zeitz  briquet  press  that  is  very  largely  used  in 
Germany.  Pressure  is  exerted  from  both  sides  at  the  same  time 
and  the  mold  can  be  exchanged  without  removing  the  mold  disk. 
Fig.  15  shows  another  form  of  briquet  press  adapted  for  all  of 
the  usual  forms  of  briquets  and  made  by  the  Konigen  Marienhutte 
Actien-Gesellschaft,  of  Cairnsdorf,  in  Saxony.  Fig.  16  shows  the 
pressroom  of  a  briquet  factory  containing  three  presses  with  a 
daily  capacity  of  3  tons. 

A  typical  example  of  a  German  briquet  factory  is  shown  in 
Figs.  17  and  18.  This  factory  is  located  at  Lauchhammer,  about 
80  miles  south  of  Berlin,  on  the  direct  line  to  Dresden,  and  is  of 


FIG.  16.     PRESSROOM  OF  BRIQUET  FACTORY 

the  latest  and  most  approved  construction.  It  has  eight  presses, 
with  the  necessary  pulverizing,  heating,  and  drying  plant,  run  by 
electric  motors  with  current  generated  by  steam  generated  with 
wood  from  the  mines.  The  whole  is  under  handsome  and  sub- 
stantial buildings  of  brick,  stone,  and  iron,  that  cost — with  tracks, 
switches,  and  full  equipment  for  handling  raw  material  and  load- 
ing the  briquets  into  cars — $371,000,  of  which  $178,500  was  paid 
for  machinery.  Each  press  weighs  32  metric  tons  and  stamps 
out  100  to  120  briquets  per  minute,  or  70  tons  in  a  double-turn 
day's  work  of  20  hours.  The  heating  and  drying  apparatus  for 
each  press  weighs  18  tons.  The  power  required  for  each  press 
and  drier  is  125  horsepower,  and  both  the  drier  and  jaws  of  the 


438 


TREATISE  ON  COKE 


TREATISE  ON  COKE 


439 


press,  between  which  the  briquets  are  squeezed  at  enormous 
pressure,  are  heated  by  exhaust  steam  from  the  Corliss  engine  in 
the  power  house,  the  whole  supply  for  the  eight  machines  being 
equivalent  to  about  150  horsepower.  Thus  equipped,  the  plant  at 
Lauchhammer  turns  out  from  500  to  600  tons  of  briquets  per  day, 
which  sell  on  cars  at  the  factory  for  from  $1.66  to  $2.14  (7  to  9 
marks),  according  to  season  and  market,  with  an  average  of  $1.90 
per  1,000  kilograms,  or  metric  ton  of  2,204  pounds. 

The  cost  of  manufacture  per  ton  of  briquets  in  Magdeburg  in 
1903,  depending  on  the  material  and  the  percentage  of  water  con- 
tained, was  stated  by  Consul  Walter  Schumann  to  be  approxi- 
mately as  follows: 


Materials 


From  lignite  taken  from  the  open  working  under  good 
conditions,  with  water  content  of  about  46  per  cent. : 

In  large  briquet  factories $1.14  to  $1.29 

In  small  briquet  factories 1.19  to     1.33 

From  lignite  taken  from  open  working,  with  water  con- 
tent of  more  than  46  per  cent,  in  large  briquet  fac- 
tories   1.33  to  1.62 

From  lignite  taken  from  the  deep  working,  with  water 
content  up  to  46  per  cent. : 

In  large  briquet  factories 1.31  to     1.62 

In  small  briquet  factories " 1.62  to     1.74 

From  lignite  taken  from  the  deep  working,  with  water 
content  of  more  than  46  per  cent.,  in  large  briquet 

factories : 1.66  to     1.86 

From  heavy  air-dried  peat,  with  30  to  40  per  cent, 
water,  reckoning  the  peat  at  66  to  71  cents  (2.8  to  3 
marks)  a  ton : 

In  briquet  factories  with  one  press 1.66  to     1.95 

In  briquet  factories  with  two  presses 1.66  to     1.86 

From  a  lighter  air-dried  peat,  with  30  to  40  per  cent. 

water,  reckoning  the  peat  at  71  cents  (3  marks)  a  ton.         2.14  to    2.38 
From  sawdust   of  soft  wood,   with   30  to  35  per  cent, 
water,   reckoning   1   ton  of  this  material  at  47  cents 
(2  marks)  in  briquet  factories  with  one  press. ........          1.62  to     1.71 

From  sawdust  of  hardwood,  with  30  to  35  per  cent, 
water,  reckoning  1  ton  of  this  material  at  47  cents 
(2  marks)  in  briquet  factories  with  one  press 1.48  to  1.62 


Cost 


In  the  case  of  materials  containing  from  15  to  18  per  cent, 
water,  for  which  a  drying  process  is  not  necessary,  the  cost  of 
manufacture  is  considerably  lower. 

Peat  as  a  material  for  fuel  ranks  in  natural  order  below  lignite, 
in  that  it  is  of  similar,  but  much  more  recent,  geologic  origin,  con- 
tains more  water,  is  but  slightly  carbonized,  and  has  a  correspond- 
ingly lower  thermal  value  than  brown  coal. 

A  pioneer  in  the  invention  of  machinery  and  processes  for 
making  compressed  peat  in  Northern  Europe  appears  to  have 


440 


TREATISE  ON  COKE 


441 


been  Mr.  C.  Schlickeysen,  of  Rixdorf,  near  Berlin.  His  first  two 
machines  were  of  vertical  construction,  and  were  built  in  1859 
for  a  steam  peat-compressing  plant  at  Zintenhof,  near  Riga, 
Russia,  where  they  worked  successfully  for  many  years,  turning 
out  daily  about  80,000  pieces  of  wet  compressed  peat,  which,  after 
drying,  were  used  as  smokeless  fuel  in  a  large  cloth  factory  at 
that  place.  During  the  ensuing  40  years,  he  has  built  peat-com- 
pressing plants  in  Holland,  Hungary,  Switzerland,  and  at  various 
places  in  Germany,  constantly  improving  his  equipment  and  proc- 
esses with  a  view  of  perfecting  the  product,  cheapening  its  cost, 
and  substituting  more  and  more  automatic  machinery  for  manual 
labor,  until  the  system  so  evolved  may  be  accepted  as  standard 
in  this  country. 

Raw  peat,  as  it  comes  from  the  bog,  contains  about  85  per 
cent,  water,   13  per  cent,  combustible  material,  and  2  per  cent. 


FIG.  19 


inorganic  matter.  To  obtain  the  13  per  cent,  of  combustible 
elements  in  the  cheapest,  most  direct  manner,  the  peat  is  cut  with 
spades  and  shoveled  into  the  trough  of  a  long,  sloping  belt-and- 
bucket  elevator,  Fig.  19,  which  carries  it  up  and  drops  it  into  a 
machine,  Figs.  20  and  21,  which  cuts,  tears,  kneads,  and  mixes 
it  to  uniform  consistency,  in  which  state  it  is  forced  out  by  a 
horizontal  screw  into  long,  plastic  skeins  about  3  in.  X  4  in.  in 
transverse  section.  These  are  delivered  at  the  tail  of  the  machine 
on  boards  3  feet  long,  which  are  lifted  off  by  hand  when  filled, 
laid  on  tram  cars,  and  run  out  to  a  clear  space,  where  they  are 
laid  in  rows  on  the  ground;  the  skeins  are  then  cut  with  a  knife 
into  bricks  or  sections  10  inches  long,  which,  being  left  to  dry, 
lose  by  exposure  in  ordinary  weather  one-half  their  water  content 
in  a  period  of  2  weeks.  The  peat  loses  by  this  machine  process 
one-third  of  its  bulk,  so  that  a  machine  that  works  742  cubic  feet 


442  TREATISE  ON  COKE 

(21  cubic  meters)  of  raw  turf  per  hour  delivers  495  cubic  feet  of 
clean  peat  or  7,000  wet  bricks  of  the  size  indicated,  which  con- 
tain from  3  to  4  tons  of  dry  compressed  peat  in  a  condition  to 
be  used  as  fuel.  Fig.  20  shows  the  inside  of  a  press  having  double 
cutting  and  mixing  knives  in  the  long  horizontal  cylinder.  Fig.  21 
shows  a  similar  machine  with  a  double  breaker  superposed.  A 
plant  of  this  kind  includes,  besides  the  elevator  and  grinding 
press,  a  10-horsepower  portable  engine,  which  is  fired  with  peat 
refuse,  and  cars  and  tracks  for  handling  the  material.  The  whole 
plant  is  movable,  is  taken  bodily  to  the  bog,  set  up  at  the  farther 
edge  of  the  moor  to  be  worked,  and  moved  backwards  as  the  peat 
bed  is  excavated  and  exhausted.  An  important  recent  improve- 


r 


FIG.  20 

ment  by  Mr.  Schlickeysen  is  an  excavating  machine,  which,  in 
moors  reasonably  free  from  logs  and  stones,  digs  and  elevates  peat 
with  great  rapidity,  thus  saving  the  hard,  wet,  unhealthy  work 
of  several  men.  The  cost  of  such  a  plant,  complete  with  engine, 
tracks,  cars,  etc.,  ready  to  operate,  is  $4,431  (18,620  marks),  and 
its  operation,  when  used  without  machine  digger,  employs  17  men 
besides  engineer  and  fireman,  a  total  cost  for  labor  in  North  Ger- 
many of  $28.56  per  day. 

A  matter  that  has  been  the  subject  of  many  serious  studies 
and  experiments  in  Germany  is  that  of  peat  coke  and  secondary 
products.  The  best  results  by  this  method  are  stated  to  be  embod- 
ied in  a  system  perfected  and  patented  by  Martin  Ziegler,  which 
gives  to  the  manufacture  of  pe? t  coke  the  dignity  of  a  perfected 
industrial  process.  The  Ziegler  method  consists  of  carbonizing 


TREATISE  ON  COKE 


443 


peat  in  closed  ovens  heated  by  burning  under  them  the  gases 
generated  by  the  coking  process  itself.  Such  a  plant  is  therefore 
self-sustaining,  the  only  fuel  required  being  coal  or  wood  sufficient 
to  heat  the  oven  for  the  first  charge,  when  the  gases  generated  by 
the  coking  process  become  available.  Not  only  this,  but  the  heat 
from  the  retort  furnaces  passes  on  and  heats  the  drying  chambers 
in  which  the  raw,  wet  peat  is  prepared  for  the  ovens  by  drying  to 
the  point  of  economical  carbonization. 

The  peat  coke  produced  as  the  primary  product  of  this  process 
is  jet  black,  resonant,  firm,  and  columnar  in  structure,  pure  as 


FIG.  21 

charcoal  from  phosphorus  or  sulphur,  and  having  a  thermal 
value  of  from  6,776  to  7,042  calories;  it  is  so  highly  prized  as  a 
fuel  for  smelting  foundry  iron,  copper  refining,  and  other  metal- 
lurgical purposes  that  it  readily  commands  from  $9.52  to  $11.90 
(40  to  50  marks)  per  ton.  It  is  also  a  high-class  fuel  for  smelting 
iron  ores,  but  as  the  process  is  comparatively  new  and  the  output 
limited,  it  is  yet  too  scarce  and  expensive  for  blast-furnace  pur- 
poses. Crushed  and  graded  to  chestnut  size,  it  forms  an  excellent 
substitute  for  anthracite  in  base-burning  stoves.  In  larger  lumps, 
as  it  comes  from  the  oven,  it  fulfils  substantially  all  the  various 
uses  of  wood  charcoal  as  a  clean,  smokeless  fuel.  The  cost  of  a 
four-oven  plant,  with  all  apparatus  for  cutting  and  drying  the 


444  TREATISE  ON  COKE 

peat,  distilling  the  gas  liquor,  and  extracting  paraffin  from  the 
tar,  is  given  at  $95,200.  Such  a  plant  has  a  capacity  of  15,000 
tons  of  peat  per  year,  the  various  products  of  which  would  sell, 
at  present  wholesale  market  prices,  for  $117,596.  A  plant  of 
twelve  ovens,  with  all  appurtenances  complete,  would  cost  $261,800 
in  Germany,  and  should  produce  annually  products  worth  $350,000, 
from  which,  deducting  the  carefully  estimated  cost  of  peat,  labor, 
depreciation  of  property,  and  other  expenses — $179,200 — there 
would  remain  a  profit  on  the  year's  operation  of  $170,800.  Consul- 
General  Mason  further  stated  in  March,  1903,  that  this  process 
is  in  successful  operation  at  Redkino,  in  Russia,  and  the  German 
government  has  evinced  its  practical  interest  in  the  subject  by 
placing  at  the  disposal  of  the  company  a  large  tract  of  peat -moor 
lands,  the  property  of  the  state,  on  which  extensive  works  will  be 
erected  during  the  coming  year. 

There  are  several  recently  patented  processes  by  which  arti- 
ficial coal,  or  briquets,  have  been  more  or  less  successfully  pro- 
duced from  peat  by  the  use  of  machinery,  or  methods,  not  yet 
fully  established  on  an  industrial  basis.  Among  these  methods 
is  the  Stauber,  which  was  first  brought  into  prominent  notice 
in  1901,  when  the  Imperial  testing  station  at  Charlottenburg 
announced,  as  the  result  of  experiments  made  with  peat  briquets 
manufactured  by  the  Stauber  system,  that  they  contained  45.14  per 
cent,  of  fixed  carbon,  4.54  per  cent,  hydrogen,  29.34  per  cent, 
oxygen,  and  9.09  per  cent,  ash,  and  had  a  thermal  value  of  3,806 
calories.  The  Stauber  system  as  thus  applied  includes  a  process 
of  rapidly  drying  moist  peat,  by  means  of  heated  and  compressed 
air  in  a  closed  chamber  or  channel,  communicating  with  conduit 
pipes  in  such  a  manner  that  heated  air  can  be  forced  through  the 
drying  channel  and  cold  air  through  the  outlet  pipe;  the  effect 
being  that  the  cold  air  rapidly  absorbs  the  hot  saturated  air  of 
the  drying  chamber  and  condenses  it  in  the  conduit  pipes,  thus 
greatly  stimulating  the  process  of  evaporation  by  which  the  peat 
is  dried.  It  is  claimed  for  the  Stauber  method  that  it  reduces 
the  moisture  to  18  or  20  per  cent,  quickly,  effectively,  and,  what  is 
most  important,  without  changing  the  chemical  composition  of  the 
peat.  The  drying  machine  is  in  the  boiler  form,  and  of  a  size  to 
conveniently  produce  5  tons  of  dried  peat  per  day.  In  a  large 
plant  this  unit  would  be  simply  repeated,  as  a  number  of  machines 
can  be  worked  with  air-currents  generated  by  the  same  engine. 
A  large  plant  for  working  the  process  was  stated  to  be  in  course 
of  erection  near  Konigsberg,  on  the  Baltic  sea,  and  another  was 
already  in  operation  at  Ostrach,  in  Wurtemburg,  in  1903.  The 
peat  coal  can  be  used  for  locomotives  or  other  fuel  raw,  or  it  can 
be  coked,  the  coke  being  wholly  free  from  sulphur,  and  is  there- 
fore as  valuable  as  charcoal  for  certain  industrial  purposes. 

Estimates  furnished  by  the  company  give  the  cost  of  a  plant 
capable  of  turning  out  50  tons  of  briquets  per  day  as  follows: 


TREATISE  ON  COKE  445 

Buildings,  $14,280;  machinery,  $17,850;  steam  engine  and  fix- 
tures, $3,570;  means  of  transporting  material  and  product,  $3,570; 
total,  $39,270. 

A  second  process  is  that  invented  by  Mr.  Schiilke,  of  Bach 
Strasse,  Hamburg,  the  salient  feature  of  which  is  that  the  turf  or 
peat  used  is  cleaned  of  roots,  stones,  etc.,  then  liquefied  by  water 
and  pumped  through  a  pipe  line  several  miles  to  the  works,  where, 
as  claimed  by  the  inventor,  it  is  leached  and  converted  by  heat 
and  pressure  into  briquets  at  a  net  cost  of  $2  per  ton,  or  into 
artificial  coal,  having  a  thermal  value  of  6,250  calories,  at  a  cost  of 
$2.50  per  ton.  It  is  understood  that  a  large  plant  is  in  progress 
of  erection  on  the  northern  coast  of  Germany  for  the  utilization  of 
this  method,  but  as  to  the  actual  condition  of  the  enterprise  or 
the  practical  value  of  the  process  on  an  industrial  scale  no  exact 
information  is  at  hand. 

Briqueting  in  Norway  and  Sweden. — Coal  has  not  as  yet  been 
discovered  in  paying  quantities  in  any  part  of  Norway,  but  peat 
of  the  best  quality  is  found  in  abundance,  and  in  some  places  is 
the  only  fuel  used  for  domestic  purposes.  It  is  generally  obtained 
in  the  old-fashioned  way,  i.  e.,  cut  with  a  spade  by  hand. 

A  society,  counting  many  prominent  Norwegians  as  members, 
has  been  formed  for  the  specific  purpose  of  utilizing  the  peat  bogs, 
which  cover  an  area  of  about  3,861  square  miles.  The  quantity 
and  quality  of  the  peat  varies  much,  of  course,  in  the  different 
bogs,  but  some  of  the  deposits  are  of  the  best  quality  and  exceed 
12  feet  in  thickness. 

Peat  briquets  are  made  and  burned  in  several  factories  located 
where  peat  is  easily  obtained.  The  machinery  used  is  built  prin- 
cipally on  the  Anreps  system;  some  is  imported  and  some  made 
at  the  machine  shops  at  Aadals  and  Hasle  Brug.  Of  the  latter, 
illustrations  and  descriptions  follow. 

The  product  of  these  machines  is  known  as  "pressed  peat," 
and  the  process  is  quite  similar  to  that  of  brickmaking.  The  peat 
is  dug  from  the  bog  and  put  into  the  machine,  where  it  is  ground 
and  then  forced  through  a  square  spout  out  upon  a  moving  plat- 
form, where  it  is  cut  into  convenient  lengths.  Thereafter  it  is 
dried,  either  in  the  open  air  or  artificially,  until  its  volume  of  mois- 
ture is  reduced  20  to  25  per  cent.  It  is  estimated  that  1.8  tons 
of  pressed  peat  equals  1  ton  of  soft  coal,  for  heating  purposes, 
while  a  ton  of  peat  made  in  the  old  way,  by  hand,  equals  only 
about  one-third  of  a  ton.  The  total  cost  of  cutting,  drying,  and 
storing  the  peat  will  not,  under  ordinary  conditions,  exceed  $1.60 
per  ton. 

Fig.  22  shows  a  4-horsepower,  steam  peat-briquet  machine, 
requiring  a  crew  of  six  men,  eight  women,  and  two  boys.  It 
delivers  20,000  briquets  per  day  and  costs  $107.  Fig.  23  shows 
a  similar  machine  to  be  operated  by  two  horses. 


446 


TREATISE  ON  COKE 


Attempts  have  also  been  made  to  manufacture  coke  from  peat, 
and  a  plant  for  that  purpose  was  built  at  Stangfjord,  in  the  neigh- 
borhood of  Bergen. 

The  partially  dried  peat  briquets  are  carbonized  in  hermetic- 
ally closed  retorts  by  electrical  heat.  The  process  allows  the  peat 
blocks  to  be  carbonized  within  a  short  time  and  with  great  uni- 
formity, while  the  peat  charcoal  produced  consists  of  a  dense  black 


FIG.  22 

mass,  showing  the  structure  of  the  peat.  The  peat  is  first  sub- 
mitted to  a  drying  and  pressing  operation,  which  is  performed  in 
a  5-horsepower  press  that  can  turn  out  about  2,500  blocks  of  peat 
per  hour,  the  weight  of  each  block  being  4.4  pounds.  The  par- 
tially dressed  and  dried  peat  briquets  are  next  loaded  on  shelf 
wagons  carrying  140  pounds  each.  When  loaded,  these  wagons 
are  pushed  into  the  cooler  end  of  the  drying  tunnel.  The  current 
of  air  passing  through  the  tunnel  is  heated  by  the  waste  gases 


FIG.  23 

from  the  retorts  and  set  in  motion  by  means  of  electrically  oper- 
ated fans.  At  the  top  end  of  the  tunnel,  where  the  wagons  emerge, 
the  temperature  of  the  air  is  90°  to  100°  C.,  and  at  the  lower  end, 
where  they  enter,  40°  to  50°  C.  The  loads  of  dry  peat  are  next 
taken  direct  into  the  retort  house  and  emptied  into  the  retorts. 
102  wagons,  two  tunnels,  three  electric  fans,  and  one  hot-air  stove 
compose  the  drying  plant  at  Stangfjord,  which  is  said  to  have  been 
able  to  produce  1,000  air-dried  peat  blocks  a  day. 


TREATISE  ON  COKE  447 

The  retorts  consist  of  upright  cylindrical  vessels  of  iron  about 
6  feet  6  inches  in  height  and  3  feet  6  inches  in  diameter,  each  retort 
being  provided  with  a  removable  cover.  The  retorts  have  spiral 
resistance  coils,  so  constructed  that  the  peat  blocks  can  be  built 
up  in  contact  with  them  until  the  mass  of  peat  entirely  fills  the 
retort,  the  heating  agent  lying  in  the  center.  The  top  cover  of 
the  retort  is  then  clamped  down  and  the  electric  current  turned 
on.  Each  retort  is  loaded  with  882  to  1,102  pounds  (400  to  500 
kilograms)  of  dried  machine-made  peat  and  the  coking  requires 
3  to  4  hours.  The  coke  thus  prepared  burns  with  a  bright  flame. 
This  process  for  carbonizing  peat  was  invented  by  Herr  P.  Jebsen, 
of  Dale,  Norway,  and  it  is  said  to  be  an  advantageous  one.  It 
has  been  in  operation  during  3  years  and  the  plant  is  now  said  to  be 
closed  on  account  of  lack  of  sufficient  capital. 

United  States  Consul  Victor  E.  Nelson  reported  on  March  7, 
1903,  from  Bergen,  Sweden,  as  follows: 

"It  is  known  that  Sweden  possesses  great  wealth  in  her  peat 
bogs,  which  are  only  awaiting  development.  The  peat  produc- 
tion of  the  world  amounts  at  present  to  from  9,000,000  to  10,000,000 
tons  a  year.  Russia  comes  first  with  about  4,000,000  tons;  peat  is 
used  there  for  locomotives  as  well  as  in  the  factories.  One  of 
the  largest  cotton  works  in  the  world  is  located  in  Russia,  and  it 
uses  peat  exclusively  as  fuel.  Most  of  the  peat  fuel  of  Sweden  is 
used  in  the  homes,  but  some  is  employed  for  industrial  purposes. 
There  are,  for  instance,  in  the  province  of  Skane,  two  factories 
using  peat  exclusively  as  fuel.  The  quality  of  the  Swedish  peat 
is  excellent,  yielding  an  inconsiderable  percentage  of  ashes.  More- 
over, the  moors  of  Sweden  are  high  and  easy  to  drain.  No  other 
European  country,  excepting  Russia,  possesses  such  an  abundance 
of  good  peat. 

"The  important  question  is  the  cost  of  manufacture.  Accord- 
ing to  one  calculation  (in  1901)  this  is  on  an  average  of  81  cents 
(3  kronor)  per  ton  for  unsheltered  peat,  to  which  must  be  added 
27  cents  (1  'krone)  per  ton  for  transportation  and  shelter.  This 
would  make  the  cost  of  the  peat  at  the  place  of  consumption 
$1.07  per  ton,  which  is  equivalent  to  coal  at  $2.14  per  ton.  For 
machine-made  briquets,  the  rate  (free  on  cart  from  the  moor) 
was  $1.34  to  $1.61  per  ton. 

"Compared  with  the  present  prices  for  wood  and  coal,  peat  is 
unquestionably  the  cheapest  fuel.  One  cord  of  pine  wood  must 
not  cost  more  than  $1.07  if  it  would  compete  with  peat  at  the 
above-mentioned  rate.  If  1  ton  of  hard  coal  is  equal  in  fuel 
value  to  1.8  tons  of  peat  (the  trial  results  vary  between  1.6  and 
1.8),  the  calculated  peat  price  would  be  equal  to  a  coal  price  of 
$2.89  per  ton — a  price  at  which  coal  cannot  be  bought  in  Sweden. 
The  government  railways,  which  are  the  largest  consumers  of  coal  jn 
this  country,  and  consequently  are  able  to  buy  cheap,  have,  during 
many  years,  paid  on  an  average  $3.75  per  ton  at  the  port  of  landing 


448  TREATISE  ON  COKE 

"The  government  and  parliament  manifest  comprehension  of 
the  great  importance  of  the  peat  industry.  The  trials  of  firing 
with  peat  on  the  Swedish  government  railways,  have,  according  to 
the  official  report,  shown  that  peat  is  about  as  expensive  as  Eng- 
lish coal,  when  the  rate  is  $2.50  for  the  former  and  $4.29  for  the 
latter,  exclusive  of  freight  charges  and  the  cost  of  loading  on  the 
tenders  of  the  locomotives." 

Engineer  Alf  Larsson,  at  a  meeting  of  the  Association  of 
National  Economy,  at  Stockholm,  in  a  lecture  on  "The  Use  of 
Our  Peat  Bogs,"  is  reported  to  have  stated  as  follows: 

"Russia  yearly  produces  4,000,000  tons  of  peat,  and  the 
Russian  Government  receives  $938,000  per  annum  for  leasing 
peat  bogs;  Germany  produces  2,000,000  and  Holland  1,000,000 
tons;  Austria,  Denmark,  Iceland,  and  other  European  countries 
also  utilize  their  deposits  of  this  cheap  fuel;  here  in  Sweden  the 
production  of  peat  for  fuel  is  about  1,000,000  tons  a  year. 

"Peat  can  be  recommended  as  a  very  good  fuel  and  its  prepa- 
ration gives  employment  to  many  persons  in  this  country.  Near 
Falkoping,  for  instance,  about  1,000  persons  are  each  summer 
employed  in  the  industry.  Peat  can  also  be  utilized  as  fuel  by 
the  paper  mills,  glass  works,  ironworks,  brick  kilns,  and  especially 
in  the  households.  The  government  engineer  for  the  peat  industry 
estimates  the  supply  of  peat  in  Sweden  to  be  4,000,000,000  tons. 
The  peat  question  is  at  present  the  most  important  problem 
in  Sweden.  The  government  has  done  some  experimenting  in 
the  matter,  with  good  results,  but  very  much  remains  to  be 
accomplished." 

Briqueting  in  Great  Britain. — Coal  briquets  for  household  use 
were  first  made  in  1877.  For  many  years  the  industry  has 
been  chiefly  carried  on  in  Wales,  where  the  coal  screenings  are 
better  adapted  to  this  use  than  any  other  quality  of  coal  produced 
in  the  United  Kingdom.  Fuel  briquets  are  made  to  a  limited 
extent  in  England  and  Scotland.  The  immense  peat  bogs  in 
Ireland,  stated  to  comprise  one-tenth  of  the  whole  country  in 
area,  should  warrant  attention  being  given  to  the  mechanical 
preparation  of  this  fuel  in  the  near  future. 

Reports  from  consuls  show  a  moderate  condition  of  the  manu- 
facture of  briquets  in  England.  Liverpool  manufactures  2,000 
to  3,000  tons  annually  at  a  cost  of  $4.87  (20  shillings)  per  ton, 
from  bituminous  coal  dust.  In  Manchester,  the  few  briquets  used 
are  made  by  the  Whitefield  Colliery  Company,  of  Staffordshire. 
They  are  about  the  size  of  an  ordinary  brick,  and  their  chief 
component  is  coal  dust  (slack),  with  a  little  tar  added.  The  price 
at  this  place  delivered  was  $2.43  (10  shillings)  for  300  briquets,  in 
December,  1902.  At  Sunderland,  the  Wear  Fuel  Works  Company, 
Limited,  at  one  time  made  briquets.  The  annual  output  was 
in  number  from  50,000  to  100,000.  The  materials  used  were 


TREATISE  ON  COKE  449 

bituminous-coal  dust  and  pitch,  the  latter  for  combining  purposes. 
The  briquet  presses  were  mainly  constructed  by  the  company 
itself,  and  two  kinds  were  used — trough  and  table.  One  of  the 
briquets  that  was  manufactured  by  this  company  evaporated  14.4 
pounds  of  water  at  212°  F.,  while  the  best  North  Country  steam 
coal  averages  14  pounds  of  water  to  1  pound  of  coal.  The  selling 
price  of  this  fuel  was  generally  equivalent  to  that  received  for  the 
best  coal.  There  are  a  few  other  places  in  England  in  which 
briquets  are  produced  in  a  small  way;  evidently,  this  manufacture 
has  not  yet  attracted  the  attention  of  coal  operators. 

In  the  latter  part  of  1902,  briqueted  fuel  was  only  produced 
in  the  Edinburgh  district  at  the  gasworks  completed  by  the  Edin- 
burgh and  Leith  Corporations  Gas  Commissioners,  at  Granton,  a 
suburb  of  Edinburgh.  At  these  works,  briquet  machinery  was 
utilized  for  the  purpose  of  working  up  the  coke  sif tings  into  fuel. 
This  residuum  of  gas  production  heretofore  was  wasted.  This 
briquet  plant  was  erected  at  a  total  cost  of  $5,000,  the  price  of 
the  machine  being  $2,250.  The  press  used  is  known  as  the  John- 
son type,  Fig.  24,  manufactured  by  Wm.  Johnson  &  Sons,  Leeds, 
England.  It  had  a  capacity  of  5  tons  per  hour.  The  coke  siftings 
were  mixed  with  pitch  and  fed  to  the  press,  the  briquets  being 
pressed  on  both  sides  simultaneously,  the  pressure  applied  equal- 
ing about  2  tons  per  square  inch.  The  plant  worked  satisfactorily, 
barring  the  tendency  to  clog  when  the  material  was  a  little  too 
wet.  The  briquets  weighed  4  pounds  each,  and  were  ready  for 
immediate  use  as  fuel,  although  it  improved  them  somewhat  to 
lie  a  week  or  10  days  in  the  open  air.  It  was  the  original  inten- 
tion to  use  these  briquets  in  the  furnaces  of  the  gasworks,  but  it 
was  found  to  be  better  economy  to  place  this  fuel  on  the  market 
for  household  purposes  at  $2.50  per  ton,  which  price  yielded  a 
good  profit.  The  Johnson  press  is  said  to  be  adapted,  also,  to 
lignite,  bituminous  coal  and  anthracite,  charcoal,  and  peat. 

Ever  since  they  were  introduced,  briquets  have  been  on  the 
market  in  East  Scotland.  During  the  last  10  years,  however, 
the  consumption  has  gradually  fallen  off.  Colliery  owners  in  dis- 
tricts where  the  coal  is  all  bituminous,  who  installed  briquet  plants, 
stopped  the  manufacture  some  years  ago,  as  the  local  demand  was 
not  sufficient  to  warrant  its  continuance,  especially  in  competition 
with  large  producers  in  West  Scotland  and  North  England. 

Briqueting  in  Wales. — Consul  Daniel  T.  Phillips  writes  from 
Cardiff,  Wales,  December  24,  1898,  as  follows: 

"The  manufacture  of  coal  briquets  known  as  patent  fuel  is 
conducted  on  an  extensive  scale  in  this  consular  district  and  else- 
where on  the  seaboard  of  the  South  Wales  coal  field,  and,  along 
with  the  general  coal  trade,  is  making  headway  every  year.  The 
first  shipment  at  Cardiff  was  in  the  year  1859,  when  4,700  tons 
was  exported;  and  last  year  the  total  reached  nearly  400,000  tons, 


450 


TREATISE  ON  COKE 


to  which  must  be  added  shipments  from  Newport  and  Swansea, 
augmenting  the  quantity  named  about  50  per  cent.  In  fact,  all 
the  fine  coal  not  used  in  the  manufacture  of  coke — for  which,  by 
the  way,  the  harder  fine  coals  are  not  suitable — is  utilized  in 
making  patent  fuel,  most  of  which  is  manufactured  in  this  district. 


FIG.  24.     JOHNSON  BRIQUET  PRESS 


The   exports  are  chiefly  to  European  ports,  at  certain  of  which 
briquets  are  also  made  on  the  spot  from  the  imported  coal. 

"A  local  manufacturer,  Mr.  T.  E.  Heath,  says  that  thirty  odd 
years  ago  the  'Coulliard'  or  ordinary  French  process  was  intro- 
duced into  Cardiff,  and,  being  found  mechanically  much  more 


TREATISE  ON  COKE  451 

perfect  than  the  old  process — which  was  both  slow  and  costly- 
soon  became  general.  The  great  majority  of  fuel  works  here  and 
abroad  are  merely  modifications  of  the  Coulliard.  When  the 
fuel  is  wanted  for  immediate  use,  it  would  be  difficult  to  get  a 
better;  but  a  great  objection  arises  from  the  steam  being  injected 
into  the  pug  mill  instead  of  having  the  mixture  dried  and  heated 
by  hot,  dry  gases.  The  steam  condenses  in  the  mixture  of  coal 
and  pitch,  and  the  blocks,  when  pressed,  contain,  therefore,  not 
only  the  original  moisture,  very  much  increased  in  wet  weather, 
but  also  the  condensed  steam  that  has  been  used  to  heat  the 
mixture.  As  the  blocks  come  from  the  press,  and  for  hours  after- 
wards, they  are  visibly  giving  off  vapor,  and  this  goes  on  in  dry 
weather  until  the  briquets  become  more  or  less  porous;  conse- 
quently, if  it  rains,  as  is  usually  the  case,  and  they  are  afterwards 
exposed  to  frost,  they  fall  to  pieces.  Such  fuel  cannot  be  stocked 
without  disintegration  and  considerable  loss  of  calorific  value; 
whereas,  fuel  made  by  a  dry-heat  process,  which  drives  out  the 
original  moisture  instead  of  adding  to  it,  will  remain  for  an  indefi- 
nite period  as  sound  as  on  the  day  it  was  manufactured.  In  fact, 
the  fuel  is  thus  superior  to  the  best  Cardiff  steam  coal,  which 
loses,  by  exposure,  more  or  less  of  its  evaporative  efficiency,  as 
the  pitch  in  the  dry-heat  fuel  prevents  the  ingress  of  moisture 
and  the  egress  of  gases. 

"In  this  district,  not  so  much  attention  is  paid  to  the  mechan- 
ical preparation  of  the  coal  used  in  briquet  manufacture  as  in 
the  varous  districts  on  the  continent  of  Europe,  where  the  coals 
are  of  a  much  poorer  quality  than  those  mined  in  South  Wales. 
Once  the  due  proportion  of  pitch  for  any  class  of  coal  has  been 
found,  the  question  of  mixing  becomes  simple.  A  briquet  is  a 
compressed  mixture  of  fine  coal  and  pitch.  The  quantity  of  the 
latter  varies  according  to  the  bituminous  matter  in  the  coal;  the 
greater  the  amount  of  bitumen  present,  the  less  pitch  is  needed. 
The  former,  being  adhesive,  performs  to  some  extent  the  same 
function  as  the  latter;  but  the  average  proportion  of  pitch  used 
is  from  7  to  9  per  cent.  The  preparation  of  the  coal  is  limited  to 
screening  at  the  colliery  and  afterwards  reducing  it  to  as  fine  a 
condition  as  possible  in  a  disintegrator,  from  which  it  is  conveyed 
to  the  mixer.  Here  it  meets  the  pitch,  and  is  then  taken  to  the 
heater.  In  each  process,  the  coal  and  pitch  are  intimately  inter- 
mixed. In  what  is  termed  the  melted-pitch  process,  the  pitch  is 
melted  (sometimes  with  additions  of  common  tar)  prior  to  being 
added  to  the  coal.  In  the  dry  method,  which  finds  more  favor, 
the  pitch  is  ground  up  with  the  coal  in  a  dry  state,  both  being 
heated  as  nearly  as  possible  to  the  firing  point  of  the  pitch,  in  an 
externally  heated  chamber,  until  each  particle  of  coal  is  covered 
with  a  film  of  melted  pitch  and  so  rendered  fit,  for  compression 
into  blocks.  The  mixture  of  paste  is  said  to  contain  from  3  to  5 
per  cent,  of  moisture,  in  order  to  facilitate  the  sliding  of  the 


452  TREATISE  ON  COKE 

particles  of  coal  on  each  other  during  compression;  but,  manifestly, 
the  heat  causes  such  moisture  to  be  thrown  off  quickly.  After 
having  been  thoroughly  mixed,  the  whole  passes  out  of  the  cham- 
ber into  a  bin,  whence  it  is  conveyed  in  buckets  of  suitable  size 
by  means  of  an  endless  chain  or  belt  to  the  press. 

"The  compressing  machines  used  may  be  roughly  divided  into 
three  classes,  irrespective  of  the  nature  of  the  power  employed. 
These  classes  are:  First,  the  single-compression  machines,  under 
which  head  should  be  placed  the  'Mazeline,'  'Stevens,'  and 
'Dupuy'  presses;  second,  machines  compressing  on  both  sides 
of  the  briquet,  such  as  the  'Middleton,'  'Bietrix,'  and  'Veillon'; 
third,  machines  acting  by  the  tangential  pressure  of  rolls,  like 
that  of  'Fouquemberg,'  and  those  of  the  sausage-machine  type, 
such  as  the  'Bourriez'  press. 

"As  far  as  this  district  is  concerned,  the  single  machines  appear 
to  be  common  and  the  shape  of  the  briquet  is  rectangular.  The 
best-looking  kind  that  I  have  seen  is  the  'sausage,'  being  about 
5  inches  in  diameter  and  to  all  appearance  a  solid  piece  of  bright 
carbon.  The  rectangular  blocks  chiefly  exported  weigh  from 
20  to  25  pounds;  and,  as  some  markets  demand  smaller  sizes,  a 
division  plate  is  inserted  in  the  mold  employed  for  the  larger  size, 
thus  reducing  it  by  one-half.  For  obvious  reasons,  the  'ovoid' 
form  of  briquet  is  common,  because,  there  are  no  corners  to  chip 
off  in  the  handling. 

"Hot  from  the  press,  the  briquets  have  little  cohesion,  and 
must  therefore  be  treated  with  care  in  stocking  and  in  loading. 
The  endless  belt  saves  a  deal  of  labor  both  at  the  factory  and  at 
the  ship's  side,  the  donkey  engine  in  the  latter  case  being  utilized 
in  working  an  endless  'hopper'  at  the  side  of  the  vessel,  so  that 
while  one  laborer  is  putting  briquets  on  at  the  bottom,  another 
laborer  is  employed  in  taking  them  off  at  the  top  and  handing 
them  to  the  loaders  on  the  vessel. 

"Inquiries  as  to  the  cost  of  labor,  fuel,  supplies,  and  mainte- 
nance of  a  briquet  factory  show  an  average  of  half  a  dollar  per  ton, 
exclusive  of  the  cost  of  materials. 

"It  should  be  noted  that  almost  any  resinous  or  tarry  matter 
may  be  used.  For  instance,  seaweed  boiled  in  water  for  some  hours 
produces  a  glutinous  mass,  and  acts  as  a  good  binding  material 
if  mixed  with  the  coal  dust  in  the  pan.  Again,  fine  sawdust,  in 
the  proportion  of  7J  per  cent.,  mixed  with  the  coal  dust  before 
going  into  the  pan,  improves  the  quality  of  the  briquet.  Of  course, 
the  quantity  of  each  binding  material  can  be  best  ascertained  by 
experiment.  Locally,  'soft  medium'  pitch  is  used.  Pitch,  being 
a  waste  product,  is  subject  to  fluctuation,  both  in  quantity  and 
in  price;  and  at  times  a  pitch  famine,  as  in  the  year  1895,  sends 
the  price  so  high  as  to  make  the  manufacture  of  patent  fuel 
unprofitable.  The  inventive  American  has  here  an  opportunity 
to  make  a  fortune  by  providing  a  satisfactory  substitute  for  pitch. 


TREATISE  ON  COKE  453 

Such  substitutes  as  have  been  tried  are  said  to  have  added  1  or  2 
per  cent,  of  ash,  and,  besides,  the  fuel  made  by  them  goes  to  pieces 
in  the  first  shower  of  rain. 

"In  many  parts  of  our  coal -producing  states,  immense  dumping 
grounds  of  unused  fine  coal  might  be  utilized;  and  the  one  reason 
given  by  coal  operators  for  not  turning  their  attention  to  artificial 
fuel  is  the  scarcity  of  pitch.  This  would  not  apply  generally,  and 
where  pitch  is  obtainable  at  a  moderate  cost,  it  is  to  be  hoped  that 
immediate  attention  will  be  paid  to  this  manufacture,  and  that  else- 
where serious  efforts  will  be  made  to  invent  a  substitute  which  can 
be  produced  in  unlimited  quantities  at  a  comparatively  small  cost. 

"It  is  claimed  for  patent  fuel  that  it  is  about  twice  as  hard  as 
coal  and,  in  some  works,  the  minimum  cohesion  allowed  is  83  per 
cent,  of  lumps  to  17  per  cent,  of  dust,  the  test  being  made  in  a 
revolving  apparatus  in  which  square  chunks  of  fuel  are  picked 
up  and  let  fall  upon  an  iron  bar  screen.  According  to  Mr.  Heath, 
large  coal  in  similar  chunks,  tested  in  the  same  machine,  gives 
only  40  per  cent,  of  lumps  and  60  per  cent,  of  dust;  and  he  tells 
of  a  cargo  of  fuel,  the  cohesion  of  which  was  83.10  per  cent.,  shipped 
for  a  long  voyage  to  a  hot  climate,  which  had  a  breakage  of  only 
2.13  per  cent,  and  a  wastage  of  .88  per  cent.,  although  the  ship- 
ment was  made  in  very  wet  weather. 

"With  regard  to  calorific  qualities,  local  experiments  cited  by 
a  Mr.  Colquohoun  show,  in  three  tests,  8.41  pounds,  8.77  pounds, 
and  8.99  pounds,  respectively,  as  the  weight  of  water  evaporated 
from  1  pound  of  fuel  at  212°  F.,  the  average  evaporative  power  of 
several  of  the  best  Welsh  steam  coals  being  9.33  pounds;  so  that 
the  artificial  fuel  is  almost  equal  in  this  respect,  besides  occupy- 
ing less  space. 

"In  order  to  compete  with  Cardiff  in  the  South  American  trade, 
advantage  should  be  taken  of  local  experience  in  briquet  manu- 
facture. Those  who  intend  to  enter  the  patent-fuel  trade  will 
find  several  firms  iri  South  Wales  prepared  to  accept  orders  for 
complete  plants.  One  well-known  firm  is  the  Uskside  Engineering 
Company,  the  managing  director  of  which  is  a  Mr.  A.  J.  Stevens, 
who  has  had  considerable  experience  in  this  line,  the  postal  address 
being  Newport,  Monmouthshire. 

"As  to  the  cost  of  the  fuel  here,  I  can  only  say  that  the 
market  price  is  determined  by  that  of  coal  itself,  the  normal 
figure  being  slightly  under  $2.50  per  ton,  or  about  50  cents  below 
the  present  figures.  In  conclusion,  I  desire  to  emphasize  the 
desirability  of  establishing  the  manufacture  of  patent  fuel  in  the 
United  States,  as  I  foresee  that  it  will  be  developed  into  a  most 
important  industry." 

Briqueting  in  Canada. — A  number  of  conditions  have  encour- 
aged fuel  briqueting  in  Canada,  particularly  in  the  Province  of 
Ontario  where  there  are  practically  no  deposits  of  coal,  and,  on 


454  TREATISE  ON  COKE 

the  other  hand,  where  there  are  peat  bogs  of  greater  or  less 
size  widely  distributed.  What  Ontario  lacks  in  coal  beds  is  made 
up  by  her  wealth  of  peat  bogs,  which,  in  extent  and  wideness  of 
distribution,  are  probably  not  exceeded  by  those  of  any  other 
country  of  equal  area.  There  is  practically  no  fuel  briqueting  in 
other  parts  of  Canada.  In  addition  to  the  abundance  of  peat  in 
bogs,  the  briqueting  industry  has  been  stimulated  by  a  scarcity  of 
anthracite  and  bituminous  fuel,  on  the  occasion  of  strikes  in  coal 
fields  supplying  Ontario  with  these  forms  of  fuel.  Also,  the  splen- 
did hardwood  forests  of  Southern  Ontario  have  been  almost 
destroyed,  making  it  necessary  to  depend  on  other  sources  than 
wood  for  fuel.  Among  those  who  have  been  particularly  instru- 
mental in  placing  the  peat  manufacture  on  its  present  high  level 
in  Ontario,  are  Mr.  Alexander  Dobson,  of  Beaverton,  and  Mr. 
J.  M.  Shuttleworth,  of  Brantford;  also,  Mr.  A.  A.  Dickson,  of 
Toronto. 

It  is  stated  that  the  European  practice,  although  successful 
under  special  circumstances,  notably  cheap  manual  labor,  cannot 
be  profitably  followed  on  this  side  of  the  Atlantic.  Only  bogs  of 
an  average  depth  of  4  feet  and  upwards  and  of  considerable  area 
(at  least  100  acres),  should  be  selected,  on  account  of  the  expense 
of  the  briqueting  plant.  Two  principal  systems  are  defined  in 
making  machine  peat,  depending  on  the  treatment  of  the  raw 
material  immediately  on  raising  it  from  the  bog.  One  plan  is  to 
digest  the  peat,  with  the  addition  of  water,  into  a  liquid  mud, 
which  is  then  poured  into  molds  in  the  open  air,  and  after  losing 
some  of  its  water,  divided  into  blocks  and  allowed  to  dry.  This 
product  is  sometimes  called  "knead"  peat.  The  other,  and  more 
commonly  employed  process,  consists  of  grinding  or  mincing  the 
peat,  as  it  comes  from  the  bog,  into  a  soft,  plastic  mass,  which  is 
then  cut  into  bricks  and  dried. 

Among  the  prominent  peat  bogs  in  Ontario  are  the  Welland 
and  the  Beaverton  bogs.  The  Welland  bog  is  about  6  miles  from 
the  town  of  Welland  on  the  Welland  Canal,  and  is  owned  by  the 
Peat  Industries,  Limited,  of  Brantford.  It  covers  an  estimated 
area  of  4,000  acres,  and  varies  in  depth  from  3  to  7  feet,  averaging 
probably  5  feet.  The  Beaverton  bogs  cover  an  area  of  about 
100  acres  near  the  town  of  Beaverton,  and  are  owned  by  Mr. 
Alexander  Dobson,  of  that  place.  The  factories  at  these  two  bogs 
are  characteristic  of  peat  manufacturing  plants  in  Ontario,  and 
a  brief  description  will  be  given  of  the  methods  in  use  at  them. 

The  three  divisions  in  which  may  be  grouped  the  various 
operations  comprising  the  making  of  fuel  peat  by  what  we  may 
call  the  Canadian  process  are:  (1)  excavating;  (2)  drying; 
(3)  compressing.  Various  methods  are  adopted  for  carrying  on 
all  these  operations  according  to  the  nature  of  the  bog  and  other 
controlling  circumstances;  but  it  cannot  be  too  strongly  stated 
that  the  crux  of  the  manufacture  lies  in  drying  the  raw  material. 


TREATISE  ON  COKE 


455 


The  difficulty  consists  not  merely  in  getting  rid  of  the  water,  but 
getting  rid  of  it  at  reasonable  cost.  It  is  at  this  point  that  num- 
berless promising  processes  have  broken  down,  and  it  is  this  essen- 
tial feature  of  manufacturing  that  requires  unceasing  vigilance 
on  the  part  of  the  peat  maker 
if  his  product  is  to  be  satis- 
factory. 

Peat  bogs  are  of  two 
classes,  wet  and  dry.  In  a 
permanently  wet  bog,  the  peat 
is  submerged  in  water  that 
does  not  admit  of  being 
drained  away.  A  dredge 
floating  on  the  bog  excavates 
the  peat  in  trenches,  and  then 
follows  into  the  paths  thus 
cut  for  itself;  scows  accom- 
pany the  dredge,  each  carry- 
ing a  number  of  boxes  in 
which  to  load  the  peat.  The 
scows  are  towed  to  a  point 
from  which  the  boxes  are  con- 
veyed to  the  works  where  the 
peat  is  to  be  treated. 

For  dry  bogs,  different 
methods  are  required.  The 
word  "dry"  as  applied  to  a 
peat  bog  does  not  mean  the 
absence  of  water,  but  rather 
that  the  bog  is  not  submerged 
and  is  capable  of  being 
drained.  The  first  thing  to  be 
done  is  to  get  rid  of  the  sur- 
plus water,  for  which  purpose 
drains  or  ditches  must  be  dug. 

At  the  Welland  bog,  the 
following  system  has  been 
adopted:  Two  or  more  par- 
allel drainage  ditches  are  run 
through  the  length  of  the  bog 
660  feet  apart  and  10  feet 
wide.  They  are  sunk  through 
the  peat  into  the  clay  under- 
lying the  bog,  and  conduct 
the  water  to  the  county  ditch  with  which  they  connect.  A  series 
of  cross-ditches  is  now  run  at  right  angles  to  the  first,  intersecting 
them  at  intervals  of  50  feet  until  a  plot  of  working  area  660  feet 
square,  or  10  acres  in  extent,  has  been  ditched  and  drained. 


456  TREATISE  ON  COKE 

At  nearly  all  of  the  other  bogs  in  the  province  where  peat-fuel 
manufacture  has  been  attempted,  drainage  has  been  necessary, 
the  expense  per  acre  varying  with  the  depth  and  size  of  the  drains. 
After  draining,  the  light,  growing,  or  undecomposed  moss  is 
removed,  together  with  protruding  stumps  and  roots  of  trees,  and 
a  level  surface  is  prepared  for  the  digging  or  excavating  process, 
which  comes  next  in  order.  The  laying  of  light  tramways  on 
which  to  haul  the  peat  into  the  factory  is  the  next  preliminary. 

Usually  the  first  step  in  the  actual  harvesting  or  gathering  of 
the  peat  is  to  run  an  ordinary  farm  harrow  over  the  surface  and 
expose  a  thin  covering  of  peat  to  the  action  of  the  wind  and  sun. 
This  plan  is  employed  where  stumps  and  roots  are  numerous,  as 
on  the  Welland  bog.  When  dried  down  to  a  water  content  of 
about  45  per  cent,  the  peat  is  scraped  by  hand  over  to  the  tram- 
ways and  loaded  into  cars  to  be  transported  to  the  factory. 

At  the  Beaverton  works,  the  peat  is  conveyed  from  bin  or 
stock  pile  or  deposited  directly  from  the  tram-car.  The  air-dried 


FIG.  26.     PEAT  DIGGER 

peat  passes  into  the  hopper  of  the  "breaker"  or  disintegrating 
machine,  where  it  is  subjected  to  a  manipulation  that  breaks  up 
the  peat  fibers,  thus  permitting  the  remaining  moisture  to  be  more 
readily  liberated  in  the  drier.  Dobson's  drying  machine,  Fig.  25, 
consists  of  a  circular  sheet-iron  box,  incasing  a  horizontal  shaft 
from  which  project  radial  cast-iron  arms  about  1  foot  in  length. 
The  Dobson  drier  is  the  distinguishing  feature  of  the  Beaverton 
works.  The  principles  it  embodies  are:  Applying  the  greatest 
heat  to  the  exterior  of  the  upper  end  of  the  cylinder  where  the 
damp  peat  enters;  causing  the  flames  and  hot  gases  to  pass  along 
and  about  the  outside  of  the  revolving  cylinder,  to  the  lower  or  rear 
end  before  entering,  and  then  to  pass  back  through  the  interior  of  the 
cylinder,  traversing  the  showering  peat;  arranging  an  internal  sys- 
tem of  lifters  so  that  this  showering  of  the  peat  will  be  continuous 
and  uniform  from  side  to  side  of  the  cylinder ;  slightly  pitching  the 


TREATISE  ON  COKE 


457 


cylinder  so  that,  as  it  revolves,  the  peat  will  travel  slowly  toward 
the  discharge  end;  and  so  adjusting  the  firing  in  accordance  with 
the  proportion  of  water  present  in  the  peat  that  a  product  uniform 
in  moisture  content  will  be  the  result.  One  test  of  this  drier  for  a 
day  of  10  hours  gave  the  following  results :  Weight  of  air-dried  peat 
charged  into  drier,  29,300  pounds,  containing  34.21  per  cent,  water; 
weight  of  peat  discharged  from  drier,  23,000  pounds,  containing  16.61 
per  cent,  water.  The  weight  of  water  evaporated  was  6,300  pounds. 
The  Beaverton  method  of  excavation  is  entirely  different. 
After  the  bog  is  drained  and  leveled,  a  mechanical  and  electrically 


FIG.  27.     DICKSON  BRIQUET  PRESS 

driven  digger,  Fig.  26,  is  set  at  work,  which  travels  slowly  up  and 
down  one  or  both  sides  of  the  area  under  removal,  the  excavating 
device  working  in  the  side  or  wall  of  the  ditch. 

At  Beaverton,  this  excavator,  or  harvester,  digs,  pulverizes, 
and  spreads  the  peat  at  one  operation,  only  one  man  attending  to 
a  15-horsepower  motor,  which  handles  from  100  to  150  tons  in 
10  hours.  The  harvester  consists  of  an  endless  chain  with  special 
buckets  and  cutters,  which  cut  the  peat  the  entire  depth  of  the 
bog  and  elevate  it  to  a  point  about  8  feet  above  the  bottom  of 
the  bog.  The  machine  is  so  arranged  that  it  can  cut  any  depth 
down  to  4  feet,  the  depth  being  easily  controlled  by  the  raising 


458 


TREATISE  ON  COKE 


Q 


or  lowering  of  the  lower  end  of  the  case  containing  the  endless 
chain  with  the  cutters.  The  spreading  of  the  peat  on  the  dry 
top  of  the  bog  is  the  most  important  part  of  the  work,  as  tests 
show  that  the  moisture  can  be  reduced  to  about  36  per  cent, 
after  several  hours'  exposure  on  a  good  drying  day.  The  whole 
machine,  the  harvester  and  spreader  combined,  is  driven  by  a 
G-horsepower  electrical  motor.  The  rate  of  travel  is  from  3  feet 
to  3  feet  6  inches  per  minute,  and  the  width  of  the  cut  is  12  inches. 
Loading  the  air-dried  peat  and  tramming  it  into  the  factory  com- 
plete the  field  operations  as  practiced  at  Beaverton. 

The  final  step,  in  the  Canadian  methods  of  peat-fuel  manufac- 
ture, is  compressing  the  dried  and  powdered  peat  into  blocks  or 
bricks.  It  has  been  found  that  a  cylindrical  briquet,  about  2 
inches  long  and  about  the  same  in  diameter,  best  answers  require- 
ments, and  this  shape  is  also  a  convenient 
form  for  manufacturing. 

The  original  briqueting  apparatus 
employed  in  Ontario  was  of  the  open- 
tube  type  patented  by  Mr.  A.  A.  Dickson, 
and  known  by  his  name,  Figs.  27  and  28. 
It  was  first  set  up  at  Well  and  about  12 
years  ago,  and  since  then  the  many 
modifications  and  improvements  made 
by  the  inventor  from  time  to  time  have 
been  tested  there.  The  principle  of  this 
press  lies  in  the  fact  that  if  a  tube  of 
indefinite  length  be  fed  with  any  mate- 
rial, the  resistance  due  to  the  friction 
between  the  material  and  the  tube  will 
gradually  rise  until  no  more  can  be  forced 
in.  Peat  is  of  such  a  nature  that,  when 
once  caused  to  pack  in  the  tube,  continued  pressure  on  the  mate- 
rial generates  a  rapid  and  great  increase  in  the  frictional  resistance. 
At  the  Beaverton  works,  the  discharge  pipe  from  the  drier 
empties  into  the  shoe  of  an  elevator,  which  carries  the  dried  peat 
into  the  large  galvanized  hopper  or  bin  interposed  between  the 
drier  and  the  briqueting  press.  This  reservoir  serves  several 
important  purposes,  and  is  practically  indispensable.  It  permits 
of  a  reserve  supply  in  case  of  accident  to  the  drier;  allows  the 
dried  peat  to  cool;  and  enables  the  press  attendant,  by  drawing 
from  various  parts  of  the  bin  containing  material  differing  in 
degree  of  dryness,  to  send  to  the  press  a  supply  of  peat  practically 
uniform  in  water  content. 

The  resistance  block  press  in  use  at  Beaverton  is  the  result 
of  4  years'  experiments  carried  on  by  Mr.  Dobson.  The  press 
embodying  Mr.  Dobson's  own  idea  on  the  plan  of  the  Dickson 
press,  is  in  use  at  the  Beaverton  plant.  In  the  Dobson  press, 
Figs.  29  and  30,  friction  is  almost  entirely  eliminated,  each  die, 


FIG.  28 


TREATISE  ON  COKE 


459 


previous  to  being  recharged,  being  oiled  to  prevent  friction  of  the 
peat  against  the  die  wall  in  the  subsequent  expulsion  of  the  briquet. 
A  number  of  dies  are  employed  in  this  press,  allowing  the  briquet 
to  remain  in  each  die  during  one  cycle ;  it  is  then  subjected  to  pres- 
sure and  expelled.  The  following  is  a  description  of  the  machine: 
There  are  two  punches  in  each  machine  and  to  each  punch  a  die 
block  containing  eight  snugly  fitting  dies.  The  down  thrust  of 
the  punches  is  imparted  by  two  heavy  eccentrics  faced  with  roller 
bearings,  and  with  each  stroke  of  the  punch  the  die  block  is  turned 


FIG.  29.     DOBSON  BRIQUET  PRESS 

through  one-eighth  of  a  revolution.  Working  in  the  next  die  to 
the  compressing  punch  is  the  release  punch,  which  expels  the 
finished  briquet,  while  the  third  receives  an  oil  swab  that  coats 
the  inside  of  the  die  with  a  film  of  crude  petroleum,  to  lessen  the 
friction  and  facilitate  the  expulsion  of  the  briquet. 

The  two  punch  systems  of  the  press  act  reciprocally,  a  stroke 
being  delivered  at  every  half  revolution  of  the  eccentric  shaft. 
With  each  down  stroke,  the  compressing  punch  forms  a  briquet 
on  the  top  of  one  previously  made  in  the  same  die,  the  discharging 
punch  expels  from  the  next  die  the  bottom  or  completed  briquet 


460 


TREATISE  ON  COKE 


and  the  third  die  receives  the  coating  of  oil  from  the  oil  swab. 
It  makes  50  or  51  revolutions  per  minute,  producing  100  or  102 
briquets  per  minute.  Twenty-five  briquets  weigh  about  10  pounds, 
and  consequently  the  output  of  the  press  in  10  hours  is  about  12^ 
tons  finished  fuel. 

We   now   take   up   the   cost   of   manufacturing   the   briquets, 
both  at  Welland  and  Beaverton.     At  Welland  the  workable  depth 


PLAN,   with  left-hand  die   k>/ocK    removed 


CLEVATION 

Left   half,    with  cf/e  */oc*   '»Place 
vertical  sect  fan   through   A- 5 

FIG.  30 


of  the  bog  is  3  feet  as  against  2^  feet  at  Beaverton,  which  gives 
an  advantage  to  the  former  in  price  per  ton  of  fuel;  also,  at  Wel- 
land the  capacity  of  the  two  briqueting  presses  is  considerably 
greater  than  that  of  the  one  at  Beaverton,  while  at  each  the 
expenditure  for  labor  is  about  the  same. 


TREATISE  ON  COKE 


461 


At  Welland,  17J  tons  of  briquets  per  day  cost  as  given  in  the 

following  table : 

COST  AT  WELLAND 


Field  operations 

Attendance  on  drier. . . 
Attendance  on  presses. 
Power 


Total 


Per  Ton 

$.3771 
.1650 
.2171 
.2113 


$.9705 


Wages  have  gone  up  since  the  Welland  tests  were  made,  and 
laborers  now  get  at  least  $1.40  per  day.  This  advance  will  add 
proportionately  to  the  cost  of  manufacture. 

At  Beaverton,  12^  tons  of  briquets  per  day  cost  as  shown  here- 
with: 

COST  AT  BEAVERTON 

Per  Ton 


Field  operations                                                              .             

$.3911 

Drvintr 

.3673 

Brioueting                                       ••  

.2512 

Total                                        

$1.0096 

In  neither  case  do  the  above  figures  cover  more  than  actual 
operating  costs,  nothing  being  allowed  for  interest  on  capital 
invested,  wear  and  tear  of  machinery,  royalty  charges,  or  profits. 

COST  OF  PLANT 


Machinery,  Etc. 


Cost 


Brio  net  press 

$2  500 

Drier                                                                   .             ...         .    . 

1  350 

Breaker                                                

400 

Excavator  including  motor  

600 

Generator   tram  car   motor  and  tracks  

1  200 

Engine  and  boiler   50  horsepower 

2  000 

Shafting   belts    and  conveyers 

700 

Buildings  (brick) 

1  500 

Sundries                                              

200 

Total                                               

$10  450 

The  above  is  the  cost  of  the  plant  according  to  the  Beaverton  plan , 
with  a  capacity  of  3, 000  tons  of  briquets  per  year,  working  10  hours  per 
day,  or  6,000  to  7,000  tons  when  run  continuously  24  hours  per  day. 


462  TREATISE  ON  COKE 

In  the  following  figures  an  attempt  is  made  to  include  all  items 
of  cost  such  as  those  for  depreciation,  interest,  etc.,  which  can  only 
be  approximate. 

TOTAL  COST  OF  BRIQUETS 


Manufacturing 

Cost  of  bog 

Depreciation  of  plant. 
Interest  on  capital.  .  . 
Royalty 


Total 


Per  Ton 


$1.0000 
.0180 
.3483 
.1741 
.2500 

$1.8000 


The  price  at  which  this  Beaverton  product  sold  at  the  factory 
in  1901  and  part  of  1902  was  $3  per  ton. 

It  is  necessary  at  these  plants,  for  the  continuous  operation 
of  the  works  the  year  round,  to  harvest,  semidry,  and  stack 
during  the  summer  a  sufficient  supply  of  peat  for  the  months 
when  harvesting  is  impossible.  Another  fact  in  connection  with 
peat-fuel  briquets  is  that  the  manufactured  product  must  at  all 
times  be  kept  dry.  Contact  with  water  renders  the  peat  practi- 
cally valueless  as  fuel;  hence,  the  care  in  preparing  and  housing  it 
is  of  the  utmost  importance. 

Briqueting  in  the  United  States. — The  United  States  of  North 
America  has  been  so  amply  endowed  by  the  Creator  with  excellent 
mineral  fuels,  covering  areas  aggregating  344,450  square  miles, 
that  thus  far  very  little  attention  has  been  given  to  the  utilization 
of  coal  waste,  screenings,  bog  carboniferous  mud,  and  other  com- 
bustible matters,  in  their  manufacture  into  briquets.  With  this 
great  abundance  of  good  mineral  coal  so  widely  distributed,  it 
may  be  submitted,  as  a  general  principle,  that  from  its  moderate 
cost,  ranging  from  $1.50  to  $6  per  ton,  it  is  evident  that,  except 
in  special  localities,  the  manufacture  of  combustible  matters  into 
briquets  could  not  be  made  with  profit  in  competition  with  the  coal. 

Efforts  have  been  made  in  Canada  to  briquet  bog  material, 
as  already  described,  but  at  the  low  rate  of  manufacture  there 
attained,  on  account  of  the  reduced  heating  power  of  peat  briquets 
as  compared  with  coal,  the  latter  would  command  the  preference 
in  the  United  States. 

Some  efforts  have  been  made  to  manufacture  briquets  from 
coal  screenings  and  coal  dust,  but  these  so  far  have  not  been  dis- 
tinguished as  successful  enterprises.  Even  with  coal  screenings 
at  50  to  60  cents  per  ton,  using  6  to  10  per  cent,  of  pitch  for  bond- 
ing matter  at  $12  to  $13  per  ton,  with  the  necessary  labor  in 
preparation  and  manufacture,  the  cost  of  briquets  would  prob- 
ably reach  $2.25  to  $2.75  per  ton. 


TREATISE  ON  COKE  463 

At  the  Hazleton  meeting  of  the  American  Institute  of  Mining 
Engineers,  in  October,  1874,  a  Mr.  Loseau  exhibited  some  egg- 
shaped  briquets  made  from  anthracite  culm  or  waste  screenings, 
but  this  exhibit  failed  to  impress  its  value  at  that  time.  Undoubt- 
edly, thousands  of  tons  of  this  culm  have  been  wasted.  This 
material  affords  when  washed  the  best  substance  for  the  manu- 
facture of  briquets,  especially  for  domestic  uses.  Even  now  it 
offers  a  practicable  field  for  this  industry.  The  culm  produced  from 
the  usual  annual  output  of  50,000,000  tons  of  anthracite  affords  an 
ample  supply  of  this  material  for  several  briqueting  plants. 

About  the  year  1890,  the  Lehigh  and  Wilkes-Barre  Coal  Com- 
pany, at  Audenreid,  Pennsylvania,  installed  a  large  briqueting 
plant  to  make  briquets  from  anthracite  culm.  The  culm  was 
received  in  a  large  storage  bin,  from  which  it  was  elevated  to 
an  automatic  mixer,  into  which  5  to  10  per  cent,  of  pitch  was 
thoroughly  blended  with  the  culm.  From  the  mixer  this  compost 
was  conveyed  to  a  cylindrical  drier  and  thence  to  the  briqueting 
press  which  made  briquets  4  in.  X  4  in  X  9  in.  When  thoroughly 
dried,  these  were  tested  in  the  small  locomotives  at  the  mines, 
but  did  not  prove  successful.  It  was  concluded  that  the  briquets 
were  too  large  and  smaller  sizes  were  made,  but  these,  also,  on 
trial,  were  not  considered  a  success.  The  plant  was  therefore 
abandoned.  After  being  out  of  use  a  year  or  more,  Mr.  Thomas 
A.  Edison  came  to  Audenreid  and  looked  over  the  plant  and  pur- 
chased it.  He  removed  it  to  his  magnetic  iron-ore  plant  in  New 
Jersey,  where  it  was  used  in  making  briquets  from  the  magnetic 
iron-ore  dust,  until  the  whole  plant  was  abandoned. 

Next  to  the  anthracite  culm  waste,  the  waste  of  breeze  at 
the  several  coke  works  offers  very  desirable  material  for  the  manu- 
facture of  briquets.  About  2  to  3  per  cent,  of  breeze  is  made  in 
the  manufacture  of  coke.  As  the  United  States  produced,  in  the 
year  1902,  23,090,342  net  tons  of  coke,  the  amount  of  breeze  at 
the  low  estimate  of  2  per  cent,  would  be  461,806  net  tons  of  clean 
coke  dust  for  briqueting.  All  or  nearly  all  of  this  is  at  present 
wasted.  It  is  quite  probable  that  this  coke  breeze  could  be 
secured  for  the  removing  of  it  from  the  coke  works,  or  at  most 
at  a  mere  nominal  price.  Briquets  could  therefore  be  made  at 
a  moderate  cost.  Briquets  made  from  anthracite  culm  and  coke 
breeze  would  be  very  nearly  smokeless,  the  only  smoke-producing 
substance  being  the  pitch  used  in  bonding  these  materials. 

Much  of  the  great  lignite  deposits  of  the  United  States  could 
be  manufactured  into  briquets  with  a  minimum  percentage  of 
the  binding  materials.  This  would  compact  this  fuel  and  render 
its  handling  and  use  quite  acceptable. 

In  connection  with  fuel  briqueting  in  the  United  States, 
Consul-General  Frank  H.  Mason,  of  Berlin,  Germany,  under  date 
of  November  20,  1902,  reported  as  follows:  "The  correspondence 
received  during  the  past  month  from  nearly  every  state  and 


464  TREATISE  ON  COKE 

territory  of  the  Union,  making  inquiry  concerning  the  machinery 
and  processes  employed  in  Germany  for  making  fuel  briquets 
from  lignite,  peat,  and  coal  dust,  indicates  that  public  interest  in 
the  whole  subject  of  utilizing  the  hitherto  wasted  or  neglected  fuel 
materials,  so  abundant  in  America,  has  been  thoroughly  aroused. 

"There  are  in  New  England,  Western  New  York,  Michigan, 
Illinois,  Wisconsin,  Oregon,  Washington,  the  two  Dakotas,  and 
the  Gulf  States,  large  deposits  of  lignite  and  material  midway 
in  character  between  lignite  and  peat,  and  there  are  in  all  the 
coal-mining  states  enormous  quantities  of  bituminous  dust  and 
anthracite  culm,  all  of  which  may,  by  the  employment  of  modern 
machinery  and  processes,  be  added  to  the  fuel  supply  of  the 
United  States."  This  is  an  industry  in  which  the  first  tentative 
efforts  made  in  the  United  States  have  generally  failed,  but  which 
has  been  developed  in  European  countries  into  an  important  and 
successful  system  of  production. 

Samples  of  lignite  from  near  Bismark,  North  Dakota,  and 
from  Troy,  Alabama,  have  been  received  at  the  German  Consulate, 
turned  over  to  a  German  briqueting  syndicate,  and  molded 
experimentally  into  briquets  with  entire  success.  The  Dakota 
lignite  is  old  and  hard,  containing  38  per  cent,  cf  water,  but 
crushes  and  pulverizes  easily  and  forms,  without  binder,  briquets 
of  firm  structure  that  burn  readily,  are  practically  smokeless, 
and  leave  only  4  per  cent,  of  ash,  while  the  best  German  brown- 
coal  briquets  yield  from  9  to  12  per  cent,  of  inorganic  residue. 
The  percentage  of  water  contained  is  rather  low,  but  by  adapting 
the  heating  and  drying  process  to  that  proportion  of  moisture, 
this  obstacle,  such  as  it  is,  can  be  easily  met,  and  the  reduced 
task  of  evaporation  will  be  an  economy  in  the  general  process. 
The  Alabama  lignite,  on  the  other  hand,  is  an  ideal  material, 
and  from  the  one  sample  submitted,  it  is  conceded  in  Germany 
to  be  even  superior  to  the  standard  brown  coals  of  Germany. 
It  contains  the  direct  percentage  of  moisture,  crushes  easily,  and 
molds  readily  into  firm,  shining,  black  briquets.  The  importance 
of  these  simple  demonstrations  will  be  inferred  from  the  fact  that, 
according  to  a  recent  State  geological  report,  there  are  55,000 
square  miles  of  lignite  beds  in  the  Dakotas  and  Montana,  all  near 
the  surface  of  the  ground,  and  ranging  in  depth  from  20  to  80 
feet.  The  extent  of  the  lignite  deposits  in  the  Gulf  States  is 
perhaps  less  exactly  known,  but  they  certainly  cover  a  large  area. 

When,  some  10  years  ago,  the  attention  of  American  iron 
makers  was  called  to  the  German  system  of  making  blast-furnace 
coke  in  retort  ovens,  which  save  the  valuable  volatile  elements 
of  the  coal,  it  was  thought  worth  while  by  certain  of  them  to 
bring  over  two  carloads  of  Connellsville  coal  to  be  coked  as  a  test 
by  the  German  process.  The  complete  success  of  that  experi- 
ment decided  the  introduction  of  the  standard  German  type  of 
coking  ovens  in  the  United  States. 


TREATISE  ON  COKE  465 

Something  similar,  it  would  seem,  might  profitably  be  done 
with  the  materials  that  Americans  have  not  yet  succeeded  in 
converting  into  satisfactory  briquets.  There  are  experienced 
engineers  and  a  dozen  manufacturers  of  briquet-making  machinery 
who  would  gladly  cooperate  in  these  tests  and  would  furnish 
machinery  adapted  to  working  the  material  thus  technically 
defined.  Upon  a  basis  of  such  tests,  plans  and  estimates  could 
be  obtained  for  the  erection  of  plants  in  the  United  States  with 
specified  daily  capacity. 

As  a  result  of  the  present  widespread  interest  in  this  subject 
and  the  many  inquiries  that  have  been  received  from  mine  owners 
and  operators  for  technical  information  as  to  processes,  cost  and 
capacity  of  machinery,  etc.,  a  combination  has  been  formed 
between  three  of  the  foremost  machine  builders  in  Germany, 
whose  products  collectively  include  all  the  necessary  apparatus  for 
making  briquets  from  coal  dust,  brown  coal,  and  peat.  The 
purpose  of  this  syndicate  is  to  meet  promptly  and  efficiently 
the  American  demand  for  machinery  and  working  methods, 
which  represent  the  best  results  obtained  by  scientific  study  and 
mature  experience  in  Germany.  The  combination  is  entitled  "The 
Export  Syndicate  of  Briquet  Machinery  Manufacturers,"  with 
central  office  at  No.  59  Friedrich  Strasse,  Berlin,  and  includes 
as  members  the  Zeiter  Eisengiesserei,  at  Zeitz,  Saxony,  the 
Maschinenfabrik  Buckau,  at  Magdeburg,  and  the  Maschinenfabrik, 
at  Ehrenfeld,  Cologne. 

An  opportunity  will  be  thus  offered  for  American  mine  owners 
and  operators  to  ascertain  definitely  in  advance  the  theoretical 
value  of  their  materials  for  briquet  making  and  the  cost  of  a  plant 
of  a  given  daily  capacity. 

Meanwhile  the  same  results  can  be  reached  with  important 
saving  of  time  if  owners  of  coal  mines  or  lignite  beds  will  send 
to  the  above  address,  directly  or  through  the  Berlin  consulate, 
10-pound  samples  of  their  material  in  the  exact  condition  in  which 
it  will  be  available  in  large  quantities  for  practical  use.  The 
percentage  of  water  in  any  briquet  material  is  an  important  factor 
in  determining  how  it  best  can  be  worked. 

If  the  material  is  dry — as,  for  instance,  slack  from  a  well- 
drained  bituminous  coal  mine — the  sample  may  be  sent  in  an 
ordinary  box  or  package.  If,  on  the  other  hand,  the  slack  or 
culm  is  obtained  wet  from  a  washing  process,  or  if  the  material 
is  lignite  or  peat  from  a  bog,  the  sample  should  be  sent  in  a  tight 
tin  case,  which  will  preserve  the  exact  percentage  of  moisture  that 
will  be  encountered  when  it  is  mined  for  use  on  an  industrial  scale. 

The  postal-package  treaty  between  the  United  States  and 
Germany  provides  for  the  transmission,  by  post,  reciprocally,  of 
packages  not  exceeding  5  kilograms  (about  11  pounds  avoir- 
dupois) in  weight  at  a  uniform  rate  of  12  cents  per  pound.  Allow- 
ing for  the  weight  of  the  necessary  covering,  this  will  enable 


466  TREATISE  ON  COKE 

interested  persons  in  America  to  forward  to  Berlin  samples  of 
their  material  sufficient  in  quantity  to  be  analyzed,  submitted  to 
various  tests,  and  even  made  experimentally  into  briquets,  so  that 
its  adaptability  to  briquet  manufacture,  the  percentage  of  binder 
required,  the  calorific  value  of  the  product,  and  methods  and 
.machinery  best  adapted  to  working  it  can  be  ascertained  and 
reported  on  in  advance  by  responsible  experts,  who  are  prepared 
to  follow  up  their  estimates  by  practical  operations.  In  this  way 
the  technical  experience  and  scientific  knowledge  that  have  made 
the  briquet  industry  successful  and  important  in  Germany  will 
be  made  directly  available  by  American  operators,  who  desire  to 
begin  at  the  point  of  economic  efficiency  that  has  been  attained 
by  the  best  practice  in  Europe. 

In  addition  to  the  utilization  of  coal  and  coke  wastes  and 
lignite  for  the  manufacture  of  briquets,  there  are,  in  the  United 
States,  large  areas  of  bogs  in  the  West,  North,  and  Northeast 
that  could  be  used  in  the  production  of  briquets.  Some  of  these 
bogs  are  accumulating  at  this  time,  especially  in  the  North,  where 
frequent  rains  occur.  The  whole  operation  of  the  growth  of  these 
bogs  can  be  witnessed  in  Newfoundland,  where  the  vegetable 
matter  receives  frequent  drizzling  rains,  rotting  the  thick  surface 
of  the  mosses  and  converting  them  into  the  black  matter  called  peat. 

Consul-General  Mason  reported  the  following  in  regard  to  peat 
in  the  latter  part  of  1903: 

"There  are  in  New  England  and  in  the  Middle  and  Western 
States  vast  beds  of  peat  that  have  been  heretofore  left  neglected 
as  waste  material  in  the  economy  of  nature.  In  Alaska  and  on 
the  islands  that  lie  along  its  shores — where  the  limited  supply  of 
coal  brought  from  British  Columbia  sells  for  $20  per  ton  and  men 
perish  from  cold  for  want  of  fuel — there  is  a  practically  unlimited 
supply  of  peat  of  the  best  quality,  all  of  which  would  be  available 
as  fuel  if  carbonized  and  converted  into  coal  or  briquets.  No 
process  that  includes  air  drying  or  works  the  peat  at  ordinary 
temperatures  would  be  practicable  there  for  more  than  a  small  part 
of  each  year — the  brief  arctic  summer  of  that  northern  clime.  If 
those  vast  deposits  of  fuel  material  are  ever  successfully  utilized, 
it  must  be  by  some  process  similar  to  those  herein  described, 
whereby  the  peat  is  quickly  machine-dried  by  means  independent 
of  the  sun  or  wind  and  then  carbonized  by  heat  that  can  defy 
even  the  cold  of  an  arctic  winter.  The  electrical  method  will  be 
first  tried  on  an  industrial  scale  in  Ireland,  an  island  which,  with 
a  total  area  of  32,393  square  miles,  has  2,830,000  acres  of  peat." 

Dr.  Edward  Atkinson,  president  of  the  Boston  Manufacturers' 
Insurance  Company,  has  issued  a  pamphlet  bearing  on  the  briquet- 
ing  of  bog  materials,  and  dated  March,  1903.  He  says:  "Consul- 
General  Mason's  reports  give  minute  accounts  with  diagrams  and 
descriptions  of  the  machinery  used.  I  observe,  however,  that 
the  mechanism  described  is  almost  identical  with  the  mechanism 


TREATISE  ON  COKE  467 

that  I  invented  in  1867  for  converting  peat  into  briquets  at  the 
Indian  Orchard  Mills.  The  price  of  coal  in  that  paper-money 
era  being  very  high,  we  successfully  worked  a  peat  bog  for  many 
months  in  a  boiler  plant  of  mills  of  about  30,000  spindles,  giving 
it  up  when  coal  went  back  to  normal  prices.  But  what  we  call 
peat,  which  is  very  full  of  hqllow  fibers  of  the  grasses  that  grow 
on  the  top  of  the  moss  preserved  in  the  peat,  is  very  much  more 
difficult  to  compress,  and  takes  much  longer  to  dry  than  this  slimy, 
nearly  homogeneous  black  mud  from  the  Taunton  River.  Pro- 
fessor Norton  is  now  having  a  machine  made  on  my  original  plan 
for  the  conversion  of  this  mud  into  briquets. 

"The  only  claim  that  I  make  is  to  having  called  attention  to 
what  seems  to  me  a  great  fact,  namely,  that  the  mud  in  the  fresh 
and  salt  water  meadows,  as  well  as  the  peat  in  the  peat  bogs,  may 
be  regarded  as  a  vast  source  of  energy,  requiring  for  its  conversion 
into  heat  mechanical  appliances  rather  than  any  other,  so  as  to 
bring  these  materials  into  a  semisolid  shape,  in  which  they  may 
be  converted  into  heat  and  power." 

The  Peat  Fuel  Company  of  America  bought  out  a  small  estab- 
lishment in  New  Haven,  Connecticut,  where  coke  was  made  for 
several  years  from  salt-marsh  mud  taken  from  the  sides  of  a  tidal 
creek.  This  product  has  been  made  in  a  small  way  and  sold  in 
New  Haven  at  full  prices.  The  promoters  have  now  moved  the 
apparatus  to  a  grass  meadow  and  are  opening  bogs  in  Brookfield, 
Massachusetts,  where  the  mud  appears  to  be  composed  almost 
wholly  of  decayed  grasses.  The  areas  in  this  section  are  very 
large.  This  Brookfield  bog,  it  is  stated,  has  been  sounded  to  a 
depth  of  47  feet  without  reaching  bottom.  Fourteen  hundred 
pounds,  net  weight,  as  taken  from  the  bottom  of  a  trial  pit,  yielded 
800  pounds  of  fuel,  bone  dry.  It  is  expected  that  this  deposit 
will  yield  500  tons  of  coke,  or  1,000  tons  of  fuel  briquets  per  acre, 
for  each  foot  in  depth  below  the  sod.  This  mud  is  to  be  artificially 
dried,  molded  into  hollow  cylinders,  and  made  in  coke  of  first 
quality. 

It  is  said  that  great  deposits  of  mud  are  known  to  exist  all 
over  the  United  States:  in  the  northern  section,  in  the  hollows 
of  the  glacial  drift;  in  the  West,  in  the  swamp  lands  and  in  the 
sloughs  or  hollows  of  the  prairies;  in  the  South,  in  the  hollows 
left  by  the  great  lagoons  that  covered  an  immense  area  when  the 
waters  of  the  Gulf  of  Mexico  receded,  and  the  lowlands  or  prai- 
ries of  Texas,  Louisiana,  and  all  the  other  states  up  to  the  Ohio 
River,  were  slowly  lifted  above  the  sea  level;  and  in  the  savannas 
and  swamps  of  the  eastern  coast. 

Messrs.  Chisholm,  Boyd,  &  Co.,  of  Chicago,  have  given  briquet- 
ing  machinery  considerable  practical  attention ;  but  so  far  mainly 
in  the  interest  of  blast-furnace  work  in  briqueting  the  iron-ore 
dust  from  the  down-comer  pipe.  The  bonding  material  in  this 
operation  is  lime.  The  iron-ore  dust  with  1  to  2  per  cent,  of 

17 


468 


TREATISE  ON  COKE 


slacked  lime  (cream  of  lime)  is  thoroughly  mixed  and  wetted  into 
a  pasty  condition  in  a  large  cylinder  mixer  annex  a,  Fig.  31,  to 
the  briqueting  machine.  This  prepared  paste  is  passed  into  a 
large  pan  in  which  are  heavy  traversing  rollers  b  immediately 
over  a  circular  steel  disk  c  perforated  around  its  outward  per- 
imeter; the  heavy  rollers  press  the  prepared  material  into  these 
perforations  in  the  circular  movement  of  the  disk.  An  arm  d 
with  two  punchers  removes  the  briquets  from  the  large  disk  and 
delivers  them  on  a  conveyer  e  that  carries  them  to  any  desired 
point,  where  they  can  be  dried  for  use.  It  may  be  noted  here 
that  this  briqueting  machine  is  not  confined  to  the  treatment  of 


FIG.  31 


iron-ore  dust,  but  can  be  used  in  briqueting  any  materials  that 
can  be  prepared  for  this  purpose. 

The  Henry  S.  Mould  Company,'  of  Pittsburg,  Pennsylvania,  is 
now  making  and  testing  briqueting  machinery.  The  following 
description,  with  Fig.  32,  shows  the  general  plan  of  the  White 
coal  briqueting  press  and  apparatus  in  which  melted  pitch  is 
used  as  a  binder.  The  process  is  shown  commencing  with  fine  coal 
in  condition  for  briqueting.  Where  it  is  necessary  to  crush  or 
screen  the  coal  to  bring  it  down  to  the  proper  size,  this  oper- 
ation is  done  first  and  requires  the  proper  crushing  and  screening 
apparatus. 

The  fine  coal  is  automatically  fed  to  the  heater.  This  heater 
is  built  in  several  styles,  some  using  steam,  others  using  direct 
or  indirect  heat  as  best  adapted  to  the  coal  to  be  operated  upon. 


470  TREATISE  ON  COKE 

The  object  of  the  heater  is  to  eliminate  all  moisture  and  bring 
the  temperature  of  the  coal  up  to  about  300°  F.  It  is  desirable 
to  have  the  material  at  this  temperature  so  that  it  will  not  chill 
and  thicken  the  pitch  when  introduced  into  the  coal,  but  become 
a  plastic  mass  when  properly  mixed.  From  the  heater,  the  fine 
coal  is  deposited  at  the  end  of  the  conveying  mixer  o.  On  a 
floor  slightly  elevated  are  two  pitch  tanks  m,  having  steam  pipes 
on  the  sides  and  bottom,  the  first  one  to  melt  the  solid  pitch  and 
the  second  to  keep  the  pitch  in  a  melted  condition  for  use.  An 
automatic  measuring  device  distributes  the  pitch  in  the  proper 
proportion  to  the  coal  in  the  mixer.  The  mass  is  thoroughly 
mixed  and  conveyed  from  the  mixer  to  hopper  d  of  the  press  by 
feed-belt  5.  The  briquets  i  are  ejected  on  a  carrier  belt  e,  and 
with  slight  cooling  are  ready  for  storage  bins  or  cars. 

The  pressing  mechanism  is  very  simple.  A  rotating  crank  a 
and  pitman  b  move  the  compression  plungers  forwards  and  back- 
wards with  a  movement  exactly  the  same  as  that  of  the  piston 
rod  of  an  engine.  The  press  box  c  has  an  independent  motion, 
as  it  is  operated  by  the  cam-track  in  the  gear  through  the  cam- 
arm,  rocker-arm,  and  links.  The  press  box  remains  stationary 
at  its  rearward  position,  while  the  compression  plungers  pass 
across  its  interior  space,  pushing  the  material  ahead  of  them  and 
forcing  it  into  the  molds.  This  motion  continues  until  the  plun- 
gers have  entered  the  mold  a  sufficient  distance  to  compact  the 
material  into  solid  briquets  under  great  pressure.  The  continued 
motion  of  the  crank  will  now  start  the  compression  plungers  for- 
wards. At  the  same  instant,  the  cam  in  the  main  gear  causes  the 
press  box  to  move  forwards  at  first  with  a  motion  exactly  coin- 
ciding with  that  of  the  compression  plungers,  then  with  an  increas- 
ing speed  forwards,  thus  gaining  on  the  receding  compression 
plungers  until  their  ends  project  slightly  through  the  back  ends 
of  the  molds.  This  motion  ejects  the  briquets;  and  should  they 
stick  to  the  plungers,  they  are  displaced  by  the  knocking-off  device 
and  fall  upon  the  delivery  belt.  The  cam-track  now  returns  the 
press  box  quickly  to  its  normal,  or  rearward,  position.  The  com- 
pression plungers  at  this  time  being  at  their  forward  position, 
new  material  falls  into  the  press  box  ready  for  another  compression. 
The  motion  of  the  press  box  in  relation  to  the  hopper  above  is 
such  that  it  crowds  the  material  downwards  when  moving  rear- 
wards. Hanging  bars  also  swing  through  the  material,  breaking 
down  any  arch  that  may  have  formed  over  the  plungers.  An 
adjustment  is  provided  whereby  the  compression  plungers  may 
enter  any  desired  distance  into  the  molds. 

The  entire  operation  is  controlled  by  the  press  operator,  one 
lever  controlling  the  friction  clutch  pulley  on  the  mixer,  this  latter 
lever  also  controlling  the  heater  and  pitch  feed.  For  a  single- 
press  plant,  besides  the  press  operator,  two  men  are  required  to 
take  care  of  the  pitch  tanks  and  heater,  and  this  is  all  the  labor 


TREATISE  ON  COKE  471 

required  from  the  point  at  which  the  fine  coal  is  fed  to  the  heater 
to  the  finished  briquet  on  the  carrier  belt.  In  the  double-press 
plant,  the  presses  are  built  right-  and  left-handed,  so  that  one 
operator  can  take  care  of  both  presses.  The  pitch  tanks  are 
enlarged  so  as  to  have  capacity  for  both  presses,  and,  where  desired, 
a  single  heater  of  sufficient  capacity  will  supply  both  presses. 
An  additional  man  is  required  for  the  two-press  plant.  The  pres- 
sure on  the  White  briqueting  press  is  adjustable,  and  from  a  light 
pressure  to  20,000  pounds  per  square  inch  can  be  put  upon  the 
briquets.  It  is  said  that  by  means  of  heavy  pressure  it  is  possible 
to  successfully  briquet  bituminous  coals  with  from  4  to  5  per  cent, 
of  pitch,  whereas  from  7  to  12  per  cent,  is  the  best  done  in  foreign 
practice. 

The  capacity  of  the  press  and  size  of  the  heater  depend  on 
the  size  of  the  briquets  made.  Four  shapes  of  briquets  can  be 
made  on  the  White  press;  and  these  presses  vary  in  capacity  from 
50  to  120  tons  per  day  of  10  hours. 

Another  method  of  operation,  known  as  the  dry  process,  is 
where  the  pitch  is  broken  up  fine  and  mixed  with  the  coal,  the 
mass  put  through  a  disintegrator,  then  through  a  heater,  and 
finally  to  the  briqueting  press. 

The  price  of  the  No.  1  White  briqueting  press  complete  is 
$6,000,  but  it  is  difficult  to  give  anything  like  accurate  figures  on 
a  complete  plant  without  knowing  the  binder  or  process  to  be  used. 
The  necessary  apparatus  outside  of  power  and  buildings,  etc., 
for  a  plant  to  produce  12  tons  per  hour,  would  be  from  $35,000 
to  $40,000. 

There  are  a  number  of  binders  that  can  be  used  in  the  pro- 
duction of  coke  briquets,  some  of  which  are  secret  mixtures  and 
some  patented.  These  binders  vary  in  their  effectiveness  and 
also  in  their  cost,  ranging  from  40  cents  to  $1  per  ton  of  briquets. 
In  a  good-sized  plant,  the  total  operating  cost  should  not  exceed 
10  to  12^  cents  per  ton  of  briquets. 

During  a  recent  visit  to  portions  of  Europe,  Asia,  and  Africa, 
I  noticed  great  heaps  of  briqueted  fuel  stored  along  the  lines  of 
railroads  in  these  countries.  It  is  used  in  Palestine  on  the  rail- 
road from  the  seaport  of  Jaffa  to  the  city  of  Jerusalem,  and  in 
Egypt  on  the  railway  from  Alexandria  to  Cario.  In  Continental 
Europe,  it  is  freely  used  on  most  of  the  railroads,  especially  in 
Germany,  Belgium,  and  France.  It  is  also  coming  into  use,  in 
a  moderate  way,  in  the  British  Isles.  The  use  of  the  briqueted 
fuel  in  generating  steam  in  the  locomotives  appeared  to  afford 
ample  power  in  the  passenger-train  service,  but  these,  as  a  general 
condition,  were  quite  short  and  light  as  compared  with  the  long 
and  heavy  passenger  trains  in  the  United  States. 

In  Ulster,  Ireland,  I  was  favored  with  briquet  fuel  in  a  small 
grate  in  my  room.  At  this  hotel,  it  was  mixed  with  a  small  por- 
tion of  coal.  The  heat  derived  from  the  briquets  did  not  impress 


472 


TREATISE  ON  COKE 


i     it 


TREATISE  ON  COKE  473 

me  with  a  feeling  of  great  warmth;  just  the  opposite,  and  the 
smoke  from  the  pitchy  bonding  material  emitted  fumes  that  were 
not  at  all  pleasant.  At  this  place,  semi -bituminous  coal  for  domes- 
tic uses  cost  $6  per  ton,  so  that  the  utilization  of  the  slack  coal 
into  briquets  was  a  matter  of  economic  necessity. 

In  conclusion,  the  following  extract  is  given  from  a  report  on 
the  production  of  coal  in  1902,  by  Mr.  E.  W.  Parker: 

Prior  to  1902,  about  400  patents  had  been  issued  in  the  United 
States  on  artificial  fuels,  but  up  to  the  close  of  1901  none  had 
proved  a  commercial  success.  Mr.  Parker  gives  a  list  of  United 
States  patents  granted  since  January  1,  1902.  It  remains  to  be 
seen  whether  any  of  them  will  be  successfully  developed.  The 
list  includes  37  patents,  but  contains  no  mention  of  fuels  made 
from  petroleum  or  petroleum  residue  unless  used  in  connection 
with  coal,  lignite,  or  peat.  Neither  does  it  include  any  compounds 
that  have  for  their  object  the  increase  of  fuel  efficiency  unless 
they  are  used  in  the  manufacture  of  the  fuel  itself.  Three  patents 
were  issued  on  briqueting  machinery. 

The  steady  advance  in  the  price  of  coal — no  less  than  40  per 
cent. — which  has  taken  place  since  1808  has  stimulated  experi- 
ments looking  to  the  invention  of  artificial  fuels.  Results  obtained 
in  foreign  countries  from  the  use  of  lignite  and  peat  in  briqueted 
form  should  encourage  producers  in  the  United  States  to  try 
similar  methods  of  manufacture.  Small  sizes  of  anthracite  for- 
merly wasted  are  indeed  recovered  now  by  washeries  from  the 
old  culm  banks  and  utilized..  A  large  amount  of  coal  lost  in  the 
form  of  dust  or  finely  pulverized  material  might  also  be  put  into 
convenient  shape  for  domestic  consumption,  and  slack  now  wasted 
at  many  of  the  bituminous  mines  in  the  United  States  might  be 
used  to  advantage  if  compressed  into  briquets.  There  are  many 
indications  that  the  time  is  not  far  distant  when  these  neglected 
fuel  resources  will  be  utilized. 


'  THIRD  REPORT  OF  PROF.  CHARLES  L.  NORTON 
UPON  BOG  FUEL 

Since  making  the  earlier  report  on  the  bog  fuel,  several  new 
phases  of  the  matter  have  developed.  We  have  perfected  our 
Atkinson-Norton  machine  and  have  manufactured  or,  as  they  say 
abroad,  "machined"  a  great  amount  of  peat  in  large  and  small 
lots.  The  details  of  the  machine  are  shown  in  Fig.  33. 

With  the  examination  of  the  fuels  brought  to  us  to  run  through 
this  machine  we  have  found  a  number  of  interesting  developments. 

1.  All  the  bog  fuel  appears  to  be  capable  of  treating  by  macer- 
ation in  this  machine  so  as  to  develop  a  binder  that  causes  the 
blocks  of  soft  mud-like  material  to  become,  in  drying,  of  about 
the  densitv  and  hardness  of  hard  wood. 


474  TREATISE  ON  COKE 

2.  The  by-products  appear  to  be  much  like  the  by-products 
of  the  European  bog  matter. 

3.  No  satisfactory  coke  can  be  made  without  macerating  and 
drying  before  coking,  and  even  then  the  coke  resembles  charcoal, 
unless  coked  under  pressure. 

4.  Many  bog  samples  have  been  found  that  contain  too  great 
an  amount  of  ash  to  be  of  commercial  value. 

5.  Some  of  the  best  samples  contain  as  large  a  percentage  of 
volatile  matter  as  65  to  70  per  cent.,  making  them  apparently  of 
great  value  as  producers  of  gas. 

The  machine,  as  will  be  seen  from  the  drawings,  Fig.  33,  is 
much  like  the  Swedish  and  German  machines,  and  consists  of  a 
set  of  revolving  blades  and  cutters  incased  in  a  closely  fitting 
cylinder,  together  with  a  pair  of  Archimedean  screws  to  force  the 
bog  matter  on  to  the  cutters  and  out  through  a  conical  nozzle. 
The  whole  arrangement  is  not  unlike  the  ordinary  sausage  machine. 
There  appears  to  be  a  certain  ratio  of  cutting  to  grinding  and 
squeezing,  which  gives  the  most  dense  and  best  drying  blocks, 
and  the  success  of  any  machine  must  depend  in  large  part  on  its 
adaptability  to  the  particular  bog  matter  with  which  it  is  used. 
Those  machines  that  are  best  suited  to  a  peat  full  of  roots  and 
sticks  are  less  suited  for  use  with  some  of  the  softer  and  less  fibrous 
masses.  By  varying  the  number  of  cutters  and  the  relative  posi- 
tions of  the  forcing  screws,  the  Atkinson-Norton  machine  is  adapt- 
able to  a  wide  variety  of  peats  and  hence  is  useful  in  examining 
samples  from  different  sources. 

The  machine  is  simple  in  operation,  the  fuel  being  dumped  into 
the  hopper,  rammed  down  from  time  to  time,  and  the  finished  prod- 
uct coming  out  in  a  continuous  stream  from  the  nozzle,  is  cut  into 
blocks  and  dried  on  boards.  In  actual  commercial  practice,  both 
the  cutting  and  removing  from  the  nozzle  can  be  done  mechan- 
ically. Until  the  machine  is  set  up  and  run  on  the  bog  for  some 
time,  there  is  no  way  of  estimating  its  output  very  closely,  but  it 
is  probable  that  from  5  to  10  tons  a  day,  dry  fuel,  can  be  got 
from  the  machine  with  a  2-horsepower  motor. 

The  bog  fuel,  on  coming  from  the  machine,  may  be  air-dried 
under  ordinary  conditions  in  from  2  to  6  weeks,  and  by  supplying 
artificial  heat  in  a  much  shorter  time.  The  danger  of  cracking  in 
drying  may  be  diminished  by  regrinding  through  the  machine 
from  time  to  time  a  few  bits  of  already  dried  peat  along  with  the 
fresh  charge  of  wet  material.  After  thorough  drying,  the  blocks 
are  sensibly  waterproof  and  they  may  be  left  outdoors  without 
injury. 

The  bog  matter  that  makes  the  densest  blocks  of  the  highest 
calorific  power  is  usually  of  a  brown  color  rather  than  a  black, 
and  it  may  or  may  not  be  fibrous.  As  has  been  predicted  by 
several  writers,  the  material  highest  in  ash  comes  from  the  lower 
parts  of  those  bogs  that  are  the  settling  basins  for  rivers  and 


TREATISE  ON  COKE  475 

smaller  streams  on  considerably  higher  land  and  occasionally 
overflowing  into  the  bogs. 

To  be  of  maximum  fuel  value,  a  bog  should  yield  a  fuel  of 
high  calorific  power,  have  a  small  percentage  of  ash,  and  should 
dry  to  a  low  percentage  of  water.  Yet  perhaps  more  important 
is  it  that  the  bog  should  be  capable  of  being  drained,  and  of  such 
depth  as  to  make  it  worth  while  to  erect  a  plant  of  considerable 
size,  since  it  is  apparent  that  larger  plants  will  be  relatively  more 
economical.  The  small  bog  can  only  pay  as  a  supply  of  "machined" 
fuel  for  a  local  market  fairly  remote  from  the  coal  fields,  but  that 
they  have  a  future  in  that  direction  is  my  firm  belief. 

The  direction  in  which  we  must  look  for  the  greatest  develop- 
ment of  bog  fuel  is  in  the  matter  of  gas  production.  While  we 
do  not  yet  know  fully  the  exact  nature  of  or  amount  of  gas  from 
a  very  large  number  of  American  bogs;  it  is  clear  that  gas  in  approx- 
imately the  same  amounts  and  of  much  the  same  kind  as  that  got 
from  soft  coal  can  be  produced  from  some  of  the  New  England 
peats.  The  gas  is  nearly  free  from  sulphur,  has  a  fair  amount  of 
illuminants,  and  unless  it  proves  to  contain  too  much  carbon- 
dioxide  is  of  great  value  for  heat,  light,  and  power  purposes. 
We  shall  very  shortly  have  some  further  demonstrations  of  the 
use  of  peat  gas  in  large  gas  engines. 

The  matter  of  by-products  has  been  given  a  great  deal  of 
attention  by  us,  but  it  is  of  such  a  delicate  chemical  nature  that 
we  are  still  far  from,  having  at  hand  a  list  of  all  the  by-products 
in  measured  amounts  obtained  from  the  peat  and  bog  fuels. 

There  is  evidently  a  considerable  difference  in  the  by-products 
of  material  from  different  bogs,  among  the  most  common,  beside 
coke  and  gas,  being  ammonia,  acetic  acid,  anthracene,  creosote, 
carbolic  acid,  toluene,  phenol,  and  pitch.  The  by-products  of 
the  material  taken  from  the  Taunton  bog  were  found  to  be  as 
follows:  (1)  tar  containing  carbolic  acid,  toluene,  phenol,  benzol, 
creosote,  and  anthracene,  together  with  a  residue  of  black  pitch; 
(2)  tar  water  containing  ammonium  sulphate,  alcohol,  and  acetic 
acid;  (3)  gas,  whose  volume  was  approximately  4  cubic  feet  per 
pound  of  peat,  and  whose  calorific  power  was  about  654  British 
thermal  units  per  cubic  foot.  Coal  would  yield  perhaps  5  cubic 
feet  of  gas  of  the  same  heating  power.  The  peat  gas  is  richer  in 
illuminants. 

We  are  preparing  to  make  an  exhaustive  examination  on  large 
samples,  to  determine  as  nearly  as  may  be  the  money  value  of 
the  total  by-products. 

During  the  summer,  an  unusual  number  of  distinguished  Euro- 
pean scientists  and  engineers  have  visited  the  Institute  on  their 
way  to  or  from  St.  Louis,  and  many  have  called  attention  to 
the  less  fibrous  or  woody  conditions  of  the  bog  fuel  we  are  using 
as  compared  with  that  with  which  they  were  familiar  abroad. 
It  may  be  that  there  is  a  difference  in  the  final  condition  of  the 

VI 


476  TREATISE  ON  COKE 

decayed  hydrocarbon  masses  that  will  account  for  the  great 
amount  of  volatile  gas-producing  matter  in  some  of  our  peats, 
that  is,  65  to  70  per  cent.,  as  compared  with  40  per  cent,  for  many 
European  peats,  and  35  per  cent,  for  coal.  Of  course,  these  gas- 
eous bogs  contain  very  little  fixed  carbon. 

Respectfully  submitted, 

CHARLES  L.  NORTON. 
MASSACHUSETTS  INSTITUTE  OP 

TECHNOLOGY, 

BOSTON,  MASS.,  U.  S.  A. 

December,  1904. 


I  NDEX 


Acetic  acid,  Effect  of,  in  removing  sulphur, 

40. 

Adelaide  coke,  282. 

Advantages  of  different  coal  fields  for  loca- 
tion of  coke  plants,  396. 
Alabama  coal  and  coke,  Analyses  of,  120. 

Stewart  washery  in,  114. 

Washery  at  Brookwood,  75. 
Alaska  coal,  Analysis  of,  29. 
Alleghany  Mountain  coke,  162. 
American  Coke  Company's  plant,  375. 
Ammonia  plant,  323. 

Yield  of,  257. 

Ammonium  sulphate,  Costs  of  manufacture, 
403. 

sulphate,  Market  for,  401. 
Analyses    and    coking    qualities    of    Rocky 
Mountain  coals,  10,  17. 

of  Alabama  coal  and  coke,  120. 

of  Alaska  coal,  29. 

of  anthracite,  7. 

of  Appalachian  bituminous  coals,  8. 

of  Appalachian  coking  coals,  25. 

of  British  Columbia  and  Vancouver  coals, 
17. 

of  brown  coals  of  Texas,  12. 

of  Central  Field  coals,  9. 

of  Coahuila  Coal  Company's  coal  and  coke, 
18. 

of  coal  before  and  after  washing.  Table  of, 
113. 

of  coal,  washed  coal,  coke,  and  refuse,  98. 

of  Connellsville  coal  and  coke,  147. 

of    Connellsville    coke    from    beehive    and 
Semet-Solvay  ovens,  280. 

of  Davis  coal  and  coke,  270. 

of  different  gases,  Table  of,  246. 

of  fuels,  Table  of,  37. 

of  German  coking  coals,  Table  of,  33. 

of  Illinois  coal  and  coke,  186. 

of  Kanawha  Valley  coal  and  coke,  147. 

of  Michigan  coals,  9. 

of  Morris  Run  coal,  266. 

of  Nova  Scotia  and  New  Brunswick  coal, 
16. 

of  Pacific  coast  coal,  16., 


Analyses  of  Rocky  Mountain  and  Great  Plains 
coal  field,  17. 

of   the    several    varieties    of   coals   in    the 
Pacific  Coast  coal  fields,  13. 

of  Thomas  coal  and  coke,  271. 

of  Triassic  coals  and  cokes,  7. 

of  Tuscarawas  coal  and  coke,  335. 

of  Welsh  coal,  Table  of,  34. 

of  Western  coals,  12. 

of  Westphalian  coking  coal,  244. 

Relation  of,  to  coking  properties,  31. 
Anthracite,  21. 

Analyses  of,  7. 

,Compressive  strength  of,  360. 

fields,  5. 

fields,  Structure  of,  8. 

in  blast  furnace,  326,  354. 

necessary  to  make  one  ton  of  pig  iron,  338. 

Physical  properties  of,  326. 

screenings,  Briquets  from,  410.' 
Appalachian  bituminous  coals,  Analyses  of,  8. 

coal  field,  7. 
Appolt  coke  oven,  212. 

coke  ovens  at  Blanzy,  215. 
Ash.  Analyses  of,  98. 
Atkinson- Norton  briquet  machine,  473. 
Atlantic  Coast  Triassic  coal  fields,  7. 
Austria-Hungary,  Briqueting  in,  417. 
Axioms,  199. 

B 

Bauer  by-product  coke  ovens,  302. 
Baum  washer,  123. 

washing    plant    at    Gladbeck,    Westphalia. 

128. 

Beaverton,  Peat  plant  at,  456. 
Beehive  and  by-product  coke,  Comparison  of, 
326. 

and    Semet-Solvay   coke    plants,    Relative 
costs  and  economies,  284. 

by-product  oven,  311. 

coke  oven,  148. 

coke  oven,  construction  of,   Specifications 
for,  153. 

coke  oven,  Cost  of  making  coke  in,  346. 

coke  oven,  Yield  from,  163. 

coke,  Structure  of,  282. 
Belgian  coke  oven,  206. 


XVI 


INDEX 


Belgium,  Briqueting  in,  419. 

Cost  of  briqueting  in,  422. 

Price  of  briquets  in,  419. 
Belt  Mountain  coals,  29. 
Bennington,  Belgium  coke  ovens  at,  208. 
Benzol,  404. 

plant,  325. 

Berard's  coal-washing  machine,  63. 
Bernard  coke  oven,  294,  379. 
Bessemer  metal,  Coke  required  to  smelt,  343. 
Bk'trix  briquet  press,  427. 
Binders  for  briquets,  413. 
Bituminization  of  coal  westward,  23. 
Bituminous  coal,  21. 

coals,  Analyses  of  Appalachian,  8. 
Blanzy,  Appolt  coke  ovens  at,  215. 
Blast  furnace  charges  in  coke  tests,  285. 

furnace   experiments,    Semet-Solvay   coke, 
277. 

furnace  fuels,  from  1854  to  1902,  Table  of, 
326. 

furnaces,    comparative    work    of    fuels    in, 
Table  of,  354. 

furnace  tests,  Table  of  results,  287. 
Bog  fuel,  Report  of  Prof.  Chas.  L.  Norton,  473. 
Bourne?,  briquet  press,  432. 
Bradford  coal  breaker,  47. 
Briquet  binders,  413. 

factory  at  Lauchhammer,  437. 

fuel  in  Ireland,  471. 

machine,  Atkinson- Norton,  473. 

machine,  Bictrix,  427. 

machine,  Bourriez,  432. 

machine,  Chisholm,  Boyd  &  Co.,  467. 

machine,  Dickson,  458. 

machine,  Dobson  459. 

machine,  Dupuy,  429. 

machine,  Henry  S.  Mould  Company,  468. 

machine,  Johnson,  449. 

machine,  Wiesner,  418. 

machine,  Zeitz,  437. 

machinery     manufacturers,     The    German 
export  syndicate  of,  465. 

machines  used  in  Saxony,  437. 

material.  Samples  for  testing,  465. 

presses,  414. 

press  for  egg-shaped  fuel,  429. 
Briqxieting,  406. 

cost  of,  in  Belgium,  422. 

in  Austria- Hungary,  417. 

in  Belgium,  419. 

in  Canada,  453. 

in  France,  422. 

in  Germany,  433. 

in  Great  Britain,  448. 

in  Norway  and  Sweden,  445. 

in  the  United  States,  462. 

in  Wales,  449. 
Briquets,  Anthracite,  410. 

Carboniferous  mud,  412. 


Briquets,  Characteristics  of.  407. 

Charcoal,  411,  418. 

Coal-slack,  409. 

Coke-breeze,  410. 

coke,  Cost  of  plant  for,  430. 

Cost  of,  in  Canada,  462 

Cost  of,  in  Germany,  439. 

Heating  value  of,  419. 

Lignite,  411,  464. 

Loss  in  handling,  409. 

Methods  and  costs  of  manufacturing,  417. 

Mud,  467. 

Peat,  411. 

Petroleum,  413,  431. 

Production  of,  in  Germany,  434. 

Sawdust,  439. 

Sizes  and  shapes  of,  407. 

Standard  sizes  of,  in  France,  424. 

Weight  per  cubic  foot  of,  409. 

Welsh,  Breakage  in  handling,  453. 
British  Columbia  coal  fields,  17. 

Columbia  coals,  Analyses  of,  17. 
Brookwood,  Alabama,  washery,  75. 
Brown  coals  of  Texas,  Analyses  of,  12. 
Browney  coke  plant,  167. 
Brunck  coke  ovens,  298. 

By-product  apparatus  at  Mines  of  Campagnac, 
229. 

apparatus  at  Otto  Station,  249. 

apparatus,  Cost  of,  243. 

apparatus  for  Otto-Hoffman  ovens,  239. 

apparatus,  Schniewind,  254. 

coke-making  statistics,  134. 

coke  ovens  by  States,  135. 

coke  oyens  in  the  United  States  and  Canada 
in  1903,  400. 

ovens  in  the  United  States,  Table  of,  205. 
By-products,  Advisability  of  saving,  401. 

and  coke,  Yield  of,  258. 

from  Daube's  coke  oven,  177. 

from  Siebel  ovens,  224. 

of  the  coke  industry,  256. 

Plant  for  saving,  320. 

Value  of,  243. 

Value  of,  per  ton  of  coke.  Table,  398. 

Yield  of,  from  Morris  Run  coal,  266,  269. 


Calorific  values  of  fuels.  Laboratory  methods 

of  determining,  353. 
Cambria,  Cost  of  coke  at,  339,  340. 
Canada,  Briqueting  in,  452. 

Coal  fields  of,  16. 
Capacity  of  jigs,  95. 

of  revolving  screens,  93. 
Carboniferous  mud  briquets,  412. 
Carbonization,  Rate  of,  192. 
Carnap,  Germany,  Coal  distillation  plant  at, 

320. 
Cell  space  in  coke,  330,  351. 


INDEX 


xvn 


Cell  structure,  Laboratory  tests,  356. 
Cellulose,  21. 
Central  coal  field,  9. 

Field  coals,  Analyses  of,  9. 
Charcoal  briquets,  411,  418. 

briquets  required  to  make  one  ton  of  pig 
iron,  338. 

in  blast  furnace,  326,  354. 

Physical  properties  of,  326. 
Charging  and  coke-pushing  machinery,  315. 
Chemical  properties  of  coal,  19. 
Chisholm,  Boyd  &  Co.  briquet  machine,  467. 
Classification  and  areas  of  the  coal  fields  of 

the  United  States,  1902,  14. 
Coahuila    Coal    Company's    coal    and    coke, 
Analyses  of,  18. 

Washing  plant  at,  79. 
Coal,  Changes  during  formation  of,  21. 

consumed  in  American  cities  in  1900,  383. 

consumed  in  United  Kingdom  for  1898,  381. 

crushing,  46. 

Debituminization  of,  eastward,  Table  of,  24. 

distillation  plant  at  Matthias  Stinnes  mine, 
Germany,  320. 

field,  Appalachian,  7. 

field,  Central,  9. 

field,  Eastern  Rocky  Mountain  and  Great 
Plains,  17. 

field,  Michigan,  9. 

field,  Northern,  9. 

field,  Texas,  12. 

field,  Western,  11. 

fields,   Adaptability  of    different   types  of 
ovens,  392. 

fields,  Anthracite,  5. 

fields,  Atlantic  Coast  Triassic,  7. 

fields,  Mexican,  17. 

fields  of  British  Columbia  and  Vancouver 
Island,  17. 

fields  of  Canada,  16. 

fields  of  North  America,  1. 

fields  of  Nova  Scotia  and  New  Brunswick,  16. 

fields  of  the  United  States,  5. 

fields  of  the  United  States  for  1902,  14. 

fields  of  the  world,  1902,  Diagram  of,  2. 

fields,  Pacific  Coast,  12. 

fields,  Qualities  of  coal  and  coke  from  dif- 
ferent, 392. 

fields,  Rocky  Mountain,  11. 

Formation  and  chemical  properties  of,  19. 

Importance  of,  1. 

Impurities  in,  38. 

periods,  4. 

Principal  elements  of,  22. 

ramming  machine,  316. 

Relations  of  different  varieties,  Diagram  of, 
21. 

required  to  produce  one  ton  of  coke.  137, 
141. 

Results  of  washing,  Table  of,  113. 


Coal  slack  briquets,  409. 

used  in  manufacturing  coke  in  the  Uni*ed 
States,  140. 

Varieties  of,  22. 

washer,  Robinson,  99. 

washing,  56. 

Weight  per  bushel  of,  196. 

World's  product  of,  1901,  1902,  Diagram  of, 

3. 

Coals,  Analyses  and  coking  qualities  of  Rocky 
Mountain,  10. 

Analyses    of    British    Columbia    and    Van- 
couver, 17. 

Analyses  of  Central  Field,  9. 

Analyses  of  different  varieties,  Table.of,  22. 

Analyses  of  Michigan,  9. 

Analyses  of  Nova  Scotia  and  New  Bruns- 
wick, 16. 

Analyses  of  Pacific  Coast,  16. 

Analyses  of  the  several  varieties  of,  in  th» 
Pacific  Coast  coal  fields,  13. 

Analyses  of  Western,  12. 

and  cokes,  Analyses  of  Triassic,  7. 

and  impurities,  Specific  gravities  of,  56 

Coking  and  non-coking,  Table  of,  26. 

Coking,  Composition  of,  24. 
Coherence  in  handling  coke,  334. 
Coke,  Amount  of  coal  vised  in  manufacture  of, 
in  the  United  States,  140. 

Analyses  of  Triassic  coals  and,  7. 

Average  value  of,  in  United  States,  142. 

beehive,  Structure  of,  282. 

breeze  briquets,  410. 

briquets,  Cost  of  plant  for,  430. 

by-products,  Plant  for  saving,  320. 

cell  space,  351. 

Coal  required  to  produce  one  ton  of,  137, 
141. 

Coherence  in  handling,  334. 

Compressive  strength  of,  360. 

Cost  of,  at  Glassport,  Cambria,  and  Ger- 
many, Table  of,  339. 

Cost  of  making,  in  beehive  ovens,  346. 

Density  of,  351. 

drawer,  Hebb,  188. 

drawer,  Smith,  187. 

drawer,  Thomas,  166. 

Effect  of  type  of  ovens  on  physical  prop- 
erties of,  348. 

Effect  on,  produced  by  crushing  the  coal, 
195. 

exported  from  the  United  States,  139. 

from  compressed  fuel,  312. 

handling  machinery,  315. 

Hardness  and  cell  space  of,  Table  of,  330, 
332. 

imported  to  the  United  States,  139. 

in  blast  furnaces,  326,  354. 

in  blast  furnaces,  Tests  of,  287. 

industry,  History  and  development  of,  131. 


XV111 


INDEX 


Coke  industry,  Statistics  of,  133. 
Kentucky,  Pineville,  358. 
Laboratory  tests  of,  355. 
larry,  Electric,  362. 
making  for  profit,  369. 
making  in  by-product  ovens,  Statistics 

of,  134. 
manufacture  in  the  United  States,  Diagram 

showing  growth  of,  138. 
Melting  power  of,  343. 
oven,  Appolt,  212. 
oven,  Bauer,  302. 
oven,  Beehive,  148. 
oven,  Belgian,  206. 
oven,  Bernard,  294. 
oven,  Brunck,  298. 
oven,  Continental,  150. 
oven,  Coppee,  208. 
oven,  Daube's,  177. 
oven,  Festner-Hoffman,  260. 
oven,  Hiissner,  292. 
oven,  Lowe,  306. 
oven,  Newcastle-upon-Tyne,  148. 
'    oven,  Old  Welsh,  164. 
oven,  Oliver  plant,  150. 
oven,  Otto  beehive  by-product,  311. 
oven,  Otto- Hoffman,  235. 
oven,  Ramsay,  173. 
oven,  Rothberg,  290. 
oven,  Schniewind,  252. 
oven,  Seibel's,  223, 
oven,  Semet-Solvay,  263. 
oven,  Simon-Carves,  219. 
oven,  statement  of  Solvay  Process  Company 

for  1894,  268. 
oven,  Thomas,  164. 
oven,  Wharton,  152. 
ovens,  Adaptability  of  different  types  of, 

to  the  several  coal  fields,  392. 
ovens  at  Browney  Colliery,  167. 
ovens,  By-product,  by  states,  135. 
ovens,  By-product,  in  the  United  States  and 

Canada  in  1903,  400. 
ovens,   By-product,  in  the   United  States, 

Table  of,  205. 

ovens,  Comparison  of  types  of,  214. 
ovens.    Condition   of   coal    charged   in   the 

United  States,  141. 
ovens,  Costs  of  material  for,  176. 
ovens,    Effects    of    types    of,    on    physical 

properties  of  coke,  348. 
ovens  in  the  United  States,  134. 
ovens,  Newton-Chambers,  186. 
ovens,     Number    of,    advisable    in    plant, 

369. 
ovens  of  different  types,  Relative  economy 

of,  397. 
ovens,      Retort      and     by-product-saving, 

Introduction,  200. 
Peat,  442. 


Coke,  physical  and  chemical  properties  of, 
Table  of,  334. 

Physical  properties  of,  326,  329. 

plant,  Life  of,  371. 

plant,  Locating,  361. 

plant  location,  Comparison  of  advantages 
of  different  coal  fields  for,  396. 

Preparation  of  coals  for  the  manufacture  of, 
43. 

produced  in  the  United  States,  139. 

produced    in     the     United    States,     Table 
of,  136. 

pusher,  318. 

pushing  machinery,  315. 

Semet-Solvay,  Structure  of,  282. 

Tests  of  blast-furnace  charges  of,  285. 

Tests  of,  with  CO2,  359. 

to  make  one  ton  of  pig  iron,  338. 

to    smelt    Bessemer    metal,    Beehive    and 
Semet-Solvay,  343. 

Weight  of,  197. 

What  constitutes  pure,  333. 

yield  of  different  ovens,  342. 

yield,  Percentage  of,  in  beehive  oven,  158. 
Coking  and  non-coking  coals,  Table  of,  26. 

charge,  48-  and  72-hour,  158. 

coals,  Analyses  of  Appalachian,  25. 

coals,  Analyses  of  Durham,  25. 

coals,  German,  Table  of,  33. 

coals,  Influence  of  composition  of,  27. 

Connellsville  and  Tuscarawas  coals  in  Ger- 
many, 335. 

costs,  175. 

experiments  and  results,  192. 

Heminway  process  of,  178. 

in  heaps  or"  mounds,  145. 

in   Ramsay  and   beehive   ovens,   Table   of 
experiments,  174. 

Percentage  of  sulphur  volatilized  in,  Table 
of,  39. 

process,  The,  157. 

properties  and  fusibility,  31. 

properties  of  different  portions  of  Connells- 
ville seam,  198. 

Rate  of,  192. 

tests,  160. 

To  determine  loss  of  carbon  in,  147. 
Comparative  work  of  fuels  in  blast  furnaces, 

354. 

Comparison  of  beehive  and  by-product  coke, 
326. 

of  beehive  and  by-product  coking,  335. 

of  different  types  of  coke  ovens,  397. 

of  oven  types,  214. 
Composition  of  coking  coal,  24. 
Compressed  fuel,  Manufacture  of  coke  from, 

312. 

Condensation  plant  at  the  Julienhutte,  239. 
Condensing  plant,  Schniewind,  254. 
Condition  of  coal  charged  into  coke  ovens,  141. 


INDEX 


xix 


Conemaugh  furnace,  Coppee  ovens  at,  210. 
Connellsville  coal  and  coke,  Analyses  of,  147, 
280. 

coal,  By-products  from,  246. 

coal,  Coking,  in  Germany,  335. 

coal  in  Otto-Hoffman  ovens,  Test  of,  245. 

coal   seam,   Coking   properties   of   different 
portions  of,  198. 

coke,  Analysis  of,  147. 

coke    from    Semet-Solvay    ovens,    Experi- 
ments in  blast  furnace,  277. 

seam,  Localities  of  phosphorus  in,  Table,  41. 
Continental  Coke  Company  beehive  oven,  150. 
Coppee  coke  oven,  208. 
Coral  coke  plant,  376. 

Cost  and  production  of  Otto-Hoffman  ovens, 
Johnstown,  344. 

of  Bernard  ovens,  298. 

of   coke   at   Glassport,   Cambria,   and   Ger- 
many, Table  of,  339. 

of  coke  in  various  ovens,  Table  of,  398. 

of  coke,  Simon-Carves  oven,  222. 

of  Festner-Hoffman  ovens,  263. 

of  making  coke  in  beehive  ovens,  175,  346. 

of  making  coke  in  Bernard  ovens,  297. 

of  Seibel  ovens,  232. 

of  Semet-Solvay  plant,  265. 

of  various  ovens,  Table  of,  398. 

of  washing  coal  at  Coahuila,  97. 

of  Wharton  coke  oven,  154. 
Costs  and  economies  of  beehive  and  Semet- 
Solvay  plants,  284. 

of  manufacturing  ammonium  sulphate,  403. 

work,  and  products  of  several  types  of  coke 

ovens,  392. 

CO2,  Tests  of  coke  with,  359. 
Crushing  coal,  46. 
Culm  briquets,  410. 

D 

Daube's  economic  down-draft  coke  oven,  177- 
Debituminization    of    coals    eastward,    Table 

of,  24. 

Density  of  coke,  351. 
Diagram  of  coal  fields  of  the  world  in  1902,  2. 

of    world's   product   of   coal    in    1901    and 

1902,  3. 

Dickson  briquet  press,  458. 
Diescher  coal  washer,  71. 
Dobson's  peat-drying  machine,  455. 

briquet  press,  459. 
Dowlais,  Resttlts  of  washing  at,  105. 
Drying  machine  for  peat,  444. 
Dunbar,  Semet-Solvay  plane  at,  273. 
Dupuy  briquet  press,  The,  429. 
Durham  coking  coals,  Analyses  of,  25. 

E 

Eastern   Rocky  Mountain  and  Great   Plains 

coal  fields    17. 
Economy  of  different  types  of  coke  ovens,  397. 


Edenborn  coke  plant,  375. 

Effects  of  types  .of  coke  ovens  on  physical 

properties  of  coke,  348. 
Elliott  trough  washer,  59. 
Ernst  coke-handling  machinery,  315. 
Everett  coke-oven  gas  plant,  384. 
Exports  of  coke,  139. 


Festner-Hoffman  coke  oven,  260. 

Formation  and  chemical  properties  of  coal,  19. 

France,  Briqueting  in,  422. 

Seibel  ovens  in,  224. 

Standard  size  of  briquets  in,  424. 
Frick  Coke  Company  No.  3  Plant,  365. 
Fuel  briqueting  industry,  406. 

statistics  of  American  cities  for  1900,  383. 
Fuels,  Analyses  of,  Table,  37. 

Blast-furnace,  1854-1902,  Table  of,  326. 

in   blast    furnaces,    Comparative    work    of, 
Table,  354. 

Laboratory  methods  of  determining  calorific 

values  of,  353. 
Fusibility  and  coking  properties  of  coals,  31. 


Gases,  Table  of  Analyses  of,  246. 

Use  of,  for  steaming  at  Pratt  Mines,  169. 
Gas,  Illuminating,  from  coke  ovens,  381. 

plant  at  Everett,  384. 

plant,  Lowe,  308. 
Gelsenkirchen  Brunck  ovens,  301. 
General  conclusions  on  the  several  types  of 

coke  ovens,  392. 
Geological  section,  4. 
German  coking  coals,  Table  of,  33. 
Germany,  Briqueting  in,  432. 

Coal  distillation  plant  at  Matthias  Stinnes 
in,  320. 

Coking  Connellsville  and  Tuscarawas  coals 
in,  335. 

Cost  of  coke  in,  339. 

Production  of  briquets  in,  434. 
Gladbeck,  Baum  washery  at,  128. 
Glassport,  Cost  of  coke  at,  339. 
Graphite,  21. 

Great  Britain,  Briqueting  in,  448. 
Great  Plains  coal  field,  17. 
Greensburg,  Stein  &  Boericke  washery  at,  122. 

H 

Hartz  jig,  62. 

Heating  value  of  briquets,  419. 

Hebb  coke  drawer,  The,  188. 

Heminway  process  of  coking,  178. 

History  and  development  of  the  coke  industry, 

131. 

Horsepower  required  in  washery,  91. 
Hostetter-Connellsville  Coke  Company,  plant, 

375 


XX 


INDEX 


Hiissner  coke  oven,  292. 

coke  oven,  Coking  tests  in,  335. 
Hydrogen   to   carbon   in   various   coals,    Pro- 
portion of,  35. 


Illinois  coal  and  coke,  Analyses  of,  186. 

Illuminating  gas  from  coke  ovens,  381. 

Importance  of  coal,  1. 

Imports  of  coke,  139. 

Improvement  of  coal  effected  by  washing,  97. 

Impurities  in  coal,  38. 

in  coke,  Effect  of,  on  pig  iron,  42. 
Ireland,  Briquet  fuel  in,  471. 
Iron,  Fuel  required  to  make  one  ton  of,  338. 


Jamison  Coal  and  Coke  Con.pany  washery, 

122. 

Jigs,  Capacity  of,  95. 
Hartz,  62. 
Luhrig,  62. 
Principle  of,  51. 
Speed  and  stroke  of,  95. 
Stein,  69. 
Johnson  briquet  press,  449. 

Company,  Blast-furnace  experiments  with 

Semet-Solvay  coke  by,  277. 
Jones  &  Laughlin  Steel  Co.,  Lowe  gas  plant, 

310. 
Julienhutte,  Plant  at,  241. 

K 

Kanawha    Valley    coal    and    coke,    Analyses 

of,  147. 
Keighley,  Fred  C.  (Paper),  369. 


Laboratory  methods  of  determining  relative 
calorific  values  of  fuel,  353. 

tests  of  coke,  355. 
Lacka wanna  Iron  and  Steel  Company's  plant 

at  Lebanon,  292,  315. 
Larry,  362. 

Latrobe  coking  plant,  186. 
Lebanon,  Lackawanna  Iron  and  Steel  Com- 
pany's plant  at,  292,  315. 
Life  of  coke  plant,  371. 
Lignite  briquets,  411. 

briquets,  Cost  of,  439. 

briquets  in  the  United  States,  464. 
Lignites,  21. 
Link-belt  coal  breaker,  54. 

belt  crusher,  55. 
Lippincott  coke  plant,  375. 
Locating  coke  plants,  361. 
Lorain,     Blast-furnace     experiments     with 

Semet-Solvay  coke  at,  277. 
Loss  of  carbon  in  process  of  coking,  147. 
Lowe  coke  oven,  306. 
Luhrig  jig,  62. 


Luhrig  washer  at  Dowlais,  Wales,  101. 
washer  at  Nelsonville,  Ohio,  108. 
washer  at  Punxsutawney,  110. 

M 

Manufacture  of  coke,  145. 

of  coke  from  compressed  fuel,  312. 

of  sulphate  of  ammonia,  232. 
Map  of  coal  fields  of  the  United  States,  6. 
Market  for  tar  and  ammonium  sulphate,  401. 
Melting  power  of  coke,  343. 
Methods  and  cost  of  manufacturing  briquets, 
417. 

of  coking  coal,  145. 
Mexican  coal  fields,  17. 
Mexico,   Washing  plant   at   Coahuila,   79. 
Michigan  coal  field,  9. 
Mines  of  Campagnac,  By-product  coke  ovens 

at,  224. 

Minister  Stein  pit,  Brunck  ovens,  301. 
Montana  coals,  Coking,  29. 
Morrell  coke  plant,  364. 

Morris  Run  coal  and  coke,  Analyses  of,  266. 
Mould  Company,  Henry  S.y  briquet  machine, 

468. 
Mud  briquets,  467. 

N 

Nelsonville,  Ohio,  Luhrig  washer  at,  108. 
New  Brunswick  coal  fields,  16. 

Brunswick  coals,  Analyses  of,  16. 

Glasgow    Iron,    Coal,    and    Railway    Com- 
pany, Bernard  ovens  of,  294. 

Glasgow    Iron,    Coal,    and    Railway    Com- 
pany washery,  69. 

Newton-Chambers  system  of  coking,  186. 
Northern  coal  field,  9. 
Norway,  Briqueting  in,  445. 
Nova  Scotia,  Bernard  ovens  in,  294. 

Scotia,  coal,  Analyses  of,  16. 

Scotia  coal  fields,  16. 

Scotia,    Washery    of    New    Glasgow    Iron, 

Coal,  and  Railway  Company  in,  69. 
No.  3  Plant,  H.  C.  Frick  Coke  Company,  365. 

o 

Old  Welsh  oven,  164. 
Oliver  coke  plant,  366. 

plant,  Beehive  oven  at,  150. 
Otto  beehive  by-product  oven,  311. 

Hoffman  oven,  235. 

Hoffman  oven,  Coking  tests  in,  336. 

Hoffman  oven,  Cost  of,  243. 

Hoffman  oven,  Temperatures  in,  241. 

Hoffman  ovens  and  by-product  apparatus 
at  Otto  Station,  248. 

Hoffman  ovens  at  Everett,  Mass.,  384. 

Hoffman  ovens  at   Johnstown,   Costs  and 
production  of,  344. 


INDEX 


xxi 


Pacific  Coast  coal,  Analyses  of,  16. 

coal  fields,  Analyses  of  the  coals  in,  13. 
Peat,  21. 

briquets,  By-products,  444. 
briquets,  Cost  in  Canada,  462. 
briquets,  Cost  in  Sweden,  447. 
briquets  in  Canada,  454. 
briquets  in  Germany,  Cost  of,  442. 
coke,  442. 
digger,  456. 
drying  machine,  444. 
fuel,  439. 

harvesting  in  Canada,  455. 
manufacturing  machine,  Schlickeysen,  441. 
or  turf  briquets,  411. 
plant  at  Beaverton,  456. 
plant  at  Welland,  455. 
Percentage  of  coke  yield  from  beehive  oven, 

163. 

Petroleum  briquets,  413,  431. 
Phosphorus  in  Connellsville  seam,  Table  of,  41. 
Percentages  of,  in   Pennsylvania   coal  and 

coke,  Table,  41. 
Physical    and    chemical    properties    of    coke, 

Table.  334. 
properties  of  charcoal,  anthracite,  and  coke, 

326. 
properties  of  coke,  Effect  of  type  of  ovens 

on,  348. 
properties  of  coke,  Effects  produced  on,  by 

crushing  the  coal,  195. 

Pig  iron,  Effect  of  impurities  in  coke  on,  42. 
iron,  Fuel  required  to  make  one  ton  of,  338. 
Pineville  coke  tests,  358. 
Pittsburg  Gas  and  Coke  Company  plant  at 

Otto  Station,  248. 
Pratt  Mines,  Using  waste  gases  under  boilers 

at,  169. 
Preparation  of  coals  for  the  manufacture  of 

coke,  43. 

Presses,  Closed-mold,  415. 
for  briquets,  414. 
Open-mold,  414. 
Prices  of  coke,  139,  142. 

Production  of  coke,  Rank  of  States  and  Ter- 
ritories in  the,  143. 
Properties  of  coke,  329. 
Proportion  of  hydrogen  to  carbon  in  various 

coals,  35. 

Punxsutawney,  Liihrig  washer  at,  110. 
Purity  of  coke,  333. 

R 

Ramsay  patent  beehive  coke  oven,  173. 
Rank  of  States  and  Territories  in  the  produc- 
tion of  coke,  143. 
Rate  of  carbonization,  192. 
Rate  of  coking,  159,  161. 

Results  with  Stewart  washery,  Table  of,  116, 
120. 


Retort  and  by-product-saving  coke  ovens,  200. 

oven  plant,  Location  of,  379. 
Robinson  coal-washer  plant,  99. 

washer,  results,  Table  of,  100. 
Rocky  Mountain  coal  fields,  11. 

Mountain  coals,  Analyses  and  coking  quali- 
ties of,  10,  17. 
Rothberg  by-product  coke  oven,  The,  290. 

coke-handling  machinery,  315. 


Sampling  briquet  material,  465. 
Sandcoulee  coals,  Coking,  29. 
Sawdust  briquets,  Cost  of,  439. 
Scaife  trough  washer,  61. 
Schniewind,  F.,  Ph.  D.,  381. 

oven,  252. 

Screens,  Capacity  of,  93. 
Seibel  oven,  223. 

oven,  Dimensions  of,  226. 

ovens,  Cost  of,  232. 

ovens,  Work  of,  233. 
Semet-Solvay  coke  oven,  263. 

Solvay  coke  ovens,  Improved,  273. 

Solvaycoke,  Structure  of,  282. 

Solvay  plant  at  Dunbar,  273. 

Solvay  plant  at  Syracuse,  267. 

Solvay  plant.  Cost  of,  265. 

Solvay  plant,  Cost  of  operating,  267. 

Solvay  tests,  Comparison  of,  271. 
Shawmut  Mining  Company's  experiments  in 

coking,  Table  of.  174. 
Silica  brick,  191. 
Simon- Carves  oven,  219. 

Carves  ovens,  Cost  and  yield  of  coke  in,  222. 
Smith  coke  drawer,  187. 

Specific  gravities  of  coal  and  impurities,  56. 
Speed  and  stroke  of  jig,  95. 
Speeding  and  gearing  of  machines  in  washery, 

Table  of,  90. 

Standard  Coal  Company's  washery  at  Brook- 
wood,  Alabama,  75. 
Statistics     showing     development     of     coke 

industry,  133. 
Stedman  coal  breaker  and  disintegrator,  50, 

52. 
Stein  &  Boericke  washery,  122. 

Walter  M.,  Installation  of  Seibel  ovens,  234. 

washers,  69. 
Stewart  coal  washer,  113. 

washer,  Table  of  results  with,  116,  120. 
Strength  of  anthracite  and  coke,  360. 

of  coke,  Laboratory  tests,  357. 
Structure  of  anthracite  in  the  Appalachian 

coal  fields,  8. 

Stutz  improved  coal  washer,  65. 
Sulphate  of  ammonia,  232. 
Sulphur,  Conditions  in  which,  is  found,  45. 

Effect  of  acetic  acid  in  removing,  40. 

volatilized  in  coking,  Table.  39. 


XX11 


INDEX 


Sweden,  Briqueting  in,  445. 
Cost  of  briquets  in,  447. 

T 

Tar..  Market  for,  401. 

Temperatures  in  Otto-Hoffman  oven,  241. 

Texas,  Analyses  of  brown  coals  of,  12. 

coal  field,  12. 
Thomas  oven,  164. 

Time  required  to  make  one  ton  of  coke,  340. 
Triassic  coal  fields,  The  Atlantic  Coast,  7. 

coals  and  cokes,  Analyses  of,  7. 
Trough  washers,  57. 
Tuscarawas  coal,  Coking,  in  Germany,  335. 

u 

United    Kingdom,    Consumption    of    coal    in 

the,  381. 

States,  Briqueting  in  the,  462. 
States,  Coal  fields  of  the,  5. 
'     States,  Map  of  the  coal  fields  of  the,  6. 
Utilization   of  the   by-products   of  the   coke 
industry  by  Dr.  Bruno  Terne,  256. 


Vancouver  coals,  Analyses  of,  17. 

Island  coal  fields,  17. 
Varieties  of  coal,  20. 

w 

Wales,  Briqueting  in,  449. 

Luhrig  washer  at  Dowlais,  101. 
Washer,  Baum,  123. 

Berard's,  63. 

Diescher,  71. 

Elliott,  59. 

vScaife,  61. 

Stein,  69. 

Stewart,  113. 

Stutz,  65. 

Trough,  57. 


Washery  at  Coahuila,  Mexico,  79. 

Cost  of,  97. 

of  New  Glasgow  Iron,  Coal,  and  Railway 
Company,  70. 

Speeding    and    gearing    of    machines    in, 
Table,  90. 

Water  and  power  required  in,  91. 
Washing  coal,  56. 

coal    at    Brookwood,    Alabama,    Table    of 
results,  79. 

coal  at  Dowlais,  Results  of,  105. 

coal,  Cost  of,  97. 

coal,  Improvement  by,  97. 
Water  required  in  washery,  Table  of,  91. 
Welland,  Peat  plant  at,  455. 
Welsh  coal,  Table  of  analyses  of,  34. 
Western  coal  field,  11. 

coals,  Analyses  of,  12. 
Westphalia,  Analysis  of  coal,  244.  - 

Baum  washing  plant  at  Gladbeck,  128. 

Brunck  coke  ovens  in,  298. 
West  Virginia  coal  and  coke,  270. 

Virginia  coals  in  Semet-Solvay  ovens,  268. 
Wharton  coke  oven,  152. 

coke  oven,  Cost  of,  154. 

coke  plant,  376. 
Whitney  coke  plant,  375. 
Wiesner  briquet  machine,  418. 
Wood,  Composition  of,  21. 
Work,  costs,  and  products  of  several  types  of 

coke  ovens,  392. 

World's  product  of  coal,  from  1901   to  1902 
(Diagram),  3. 

Y 

Yield  of  coke  and  by-products,  Percentage, 

258. 
of  coke  in  different  ovens,  342. 

z 

Zeitz  briquet  press,  The,  437. 


17303-1-17-06-1200 


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